Edgar Filing: ONEOK INC /NEW/

424B5

Filed pursuant to Rule 424(b)(5)
SEC File No. 333-219186

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities, and we are not soliciting an offer to buy these securities, in any state where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED JANUARY 4, 2018

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus Dated July 6, 2017)

LOGO

19,000,000 Shares

Common Stock

We are offering 19,000,000 shares of our common stock, par value $0.01 per share, to be sold in this offering.

Our common stock is listed on the New York Stock Exchange (the “NYSE”), under the symbol “OKE.” The last reported sale price of our common stock on January 3, 2018 was $55.54 per share.

Investing in our common stock involves a high degree of risk. Before buying any common stock, you should read the discussion of material risks of investing in our common stock in “Risk Factors” beginning on page S-5 of this prospectus supplement, on page 7 of the accompanying base prospectus and the other risks identified in the documents incorporated by reference herein before making a decision to purchase common stock in this offering.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying base prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The underwriters have agreed to purchase the shares of our common stock at a price of $ per share, which will result in proceeds to us, before expenses, of $ . The underwriters intend to offer the shares of our common stock from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices. See “Underwriting” for additional information regarding compensation to be received by the underwriters.

The underwriters will have the option to purchase within 30 days from the date of this prospectus supplement up to an additional 2,850,000 shares of our common stock from us. If this option is exercised in full, it would result in approximately $ of additional proceeds to us, before expenses.

Delivery of the shares of common stock will be made on or about January , 2018.

Book-Running Manager

Credit Suisse

The date of this prospectus supplement is January , 2018.

IMPORTANT NOTICE ABOUT INFORMATION IN THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING BASE PROSPECTUS

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part is the accompanying base prospectus, which gives more general information, some of which may not apply to this offering of common stock. Generally, when we refer only to the “prospectus,” we are referring to both parts combined. If information varies between this prospectus supplement and the accompanying base prospectus, you should rely on the information in this prospectus supplement.

Any statement made in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated by reference into this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement. Please read “Where You Can Find More Information” and “Incorporation by Reference” in this prospectus supplement and the accompanying base prospectus.

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TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT


SUMMARY			S-1
RISK FACTORS			S-5
USE OF PROCEEDS			S-6
CAPITALIZATION			S-7
PRICE RANGE OF OUR COMMON STOCK			S-8
MATERIAL U.S. FEDERAL TAX CONSIDERATIONS FOR NON-U.S. HOLDERS OF OUR COMMON STOCK			S-9
UNDERWRITING			S-13
LEGAL MATTERS			S-20
EXPERTS			S-20
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS			S-20
WHERE YOU CAN FIND MORE INFORMATION			S-23
INCORPORATION BY REFERENCE			S-24

PROSPECTUS


ABOUT THIS PROSPECTUS			1
WHERE YOU CAN FIND MORE INFORMATION			1
INCORPORATION BY REFERENCE			2
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS			3
ABOUT ONEOK			6
RISK FACTORS			7
USE OF PROCEEDS			8
RATIO OF EARNINGS TO FIXED CHARGES			9
DESCRIPTION OF DEBT SECURITIES			10
DESCRIPTION OF GUARANTEE OF DEBT SECURITIES			22
DESCRIPTION OF CAPITAL STOCK			23
DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE CONTRACT UNITS			29
DESCRIPTION OF DEPOSITARY SHARES			30
DESCRIPTION OF WARRANTS			32
PLAN OF DISTRIBUTION			33
LEGAL MATTERS			35
EXPERTS			35

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SUMMARY

This summary highlights certain information about ONEOK. It is not complete and does not contain all the information that you should consider before investing in our common stock. You should carefully read this entire prospectus supplement, the accompanying base prospectus and the other documents incorporated by reference herein and therein to understand fully ONEOK and other considerations that are important in making your investment decision. Please read “Risk Factors” and the other cautionary statements in this prospectus supplement, in the accompanying base prospectus and in the documents incorporated by reference herein and therein before making a decision to purchase common stock in this offering.

Unless we otherwise indicate or unless the context requires otherwise, all references in this prospectus supplement to “we,” “our,” “us,” the “Company,” “ONEOK” or similar references mean ONEOK, Inc. and its consolidated subsidiaries and predecessors. References to “ONEOK Partners” refer to ONEOK Partners, L.P., our wholly owned subsidiary. References to the “Intermediate Partnership” refer to ONEOK Partners Intermediate Limited Partnership, a wholly owned subsidiary of ONEOK Partners, L.P.

ONEOK, Inc.

ONEOK is a corporation incorporated under the laws of the state of Oklahoma, and our common stock is listed on the NYSE under the trading symbol “OKE.” We apply our core capabilities of gathering, processing, fractionating, transporting, storing and marketing natural gas and natural gas liquids (“NGLs”) through the rebundling of services across the value chains through vertical integration in an effort to provide our customers with premium services at lower costs. We are a leader in the gathering, processing, storage and transportation of natural gas in the United States. In addition, we own one of the nation’s premier natural gas liquids systems, connecting NGL supply in the Mid-Continent and Rocky Mountain regions and the Permian Basin with key market centers.

ONEOK Partners Transaction

On January 31, 2017, we and ONEOK Partners entered into an Agreement and Plan of Merger (the “Merger Agreement”), by and among us, New Holdings Subsidiary, LLC, a subsidiary of ours (“Merger Sub”), ONEOK Partners and ONEOK Partners GP, L.L.C., the sole general partner of ONEOK Partners, for the purpose of acquiring the outstanding units of ONEOK Partners that we did not already own (the “Merger Transaction”). On June 30, 2017, our shareholders approved the issuance of our common stock to ONEOK Partners’ common unitholders pursuant to the Merger Agreement and the amendment of our amended and restated certificate of incorporation to increase the number of our authorized shares of common stock from 600 million to 1.2 billion shares, and ONEOK Partners’ unitholders approved the Merger Agreement. On June 30, 2017, pursuant to the Merger Agreement, we acquired the 171.5 million common units representing limited partner interests in ONEOK Partners not already directly or indirectly owned by us in an all stock-for-unit transaction at a ratio of 0.985 of a share of our common stock per common unit of ONEOK Partners. On the same day, Merger Sub merged with and into ONEOK Partners, with ONEOK Partners surviving as a wholly owned subsidiary of ours. In addition, we, ONEOK Partners and Intermediate Partnership, a wholly owned subsidiary of ONEOK Partners, issued, to the extent not already in place, guarantees of certain indebtedness of ONEOK and ONEOK Partners. Upon the closing of the merger, former ONEOK Partners’ common unitholders owned approximately 44% and existing ONEOK shareholders owned approximately 56% of the combined company, respectively.

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Recent Developments

The Elk Creek Pipeline Project

We plan to invest approximately $1.4 billion to construct a new pipeline (the “Elk Creek Pipeline”), and related infrastructure to transport NGLs from the Rocky Mountain region to our existing Mid-Continent NGL facilities. The Elk Creek Pipeline is expected to cost approximately $1.2 billion, with related infrastructure costs expected to total approximately $200 million. We anticipate completing the Elk Creek Pipeline by the end of 2019. The Elk Creek Pipeline, an approximately 900-mile, 20-inch diameter pipeline, will have the capacity to transport up to 240,000 barrels per day (“bpd”) of unfractionated NGLs from near our Riverview terminal in eastern Montana to Bushton, Kansas and will be capable of being expanded to 400,000 bpd with additional pump facilities.

We are adding this additional NGL takeaway capacity to meet the expected needs of our producers who are increasing production and are required to meet natural gas capture targets in the Williston Basin. We expect that the Elk Creek Pipeline will strengthen our position in the high-production areas of the Bakken, Powder River and Denver-Julesburg regions and also provide additional reliability and redundancy on our NGL system.

Supply commitments for the Elk Creek Pipeline are anchored by long-term contracts with terms ranging between 10 to 15 years totaling approximately 100,000 bpd, which is supported primarily by minimum volume commitments.

We expect to finance the Elk Creek Pipeline with a combination of net proceeds from this offering, the approximately $450 million of net proceeds received from common stock issued during 2017 under our “at-the-market” equity program, cash from operations in excess of dividends, and short- and long-term borrowings. See “Use of Proceeds”.

This project is part of our $3.0 billion to $3.5 billion of potential capital-growth projects under development. Additional projects which are in the late stages of development are expected to be announced when sufficient supply commitments are secured. We expect to finance the funding needs for these additional projects in 2018 and well into 2019 with cash generated from operations and short- and long-term borrowings.

Enacted Changes to the U.S. Tax Laws

On December 20, 2017, the U.S. House of Representatives and the U.S. Senate each voted to approve H.R. 1 (the “Tax Cuts and Jobs Act”) and, on December 22, 2017, President Trump signed the Tax Cuts and Jobs Act into law. The Tax Cuts and Jobs Act makes extensive changes to the U.S. tax laws and includes provisions that, among other things, will reduce the U.S. corporate tax rate, introduce a capital investment deduction, limit the interest deduction, limit the use of net operating losses to offset future taxable income, and make extensive changes to the U.S. international tax system, including the taxation of the accumulated foreign earnings of U.S. multinational corporations.

The reduction in the U.S. corporate tax rate will cause a revaluation of our deferred tax assets, which will result in a reduction of net income in our 2017 fiscal year, but will also reduce the amount of tax that we would be required to pay in the future due to the lower corporate tax rate. The 100% expensing of capital assets placed in service before January 1, 2023 is expected reduce our future taxes in the years those assets are placed in service. The Tax Cuts and Jobs Act is complex and far-reaching and we cannot predict with certainty the resulting impact its enactment will have on us.

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Our Principal Executive Offices

Our principal executive offices are located at 100 West Fifth Street, Tulsa, Oklahoma, 74103-4298, and our telephone number at that address is (918) 588-7000. We maintain a website at www.oneok.com that provides information about our business and operations. Information contained on this website, however, is not incorporated into or otherwise a part of this prospectus supplement or the accompanying base prospectus.

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The Offering

Shares of Common Stock Offered

19,000,000 shares of our common stock.

Shares of Common Stock Outstanding Before This Offering

388,626,237 shares of our common stock (as of January 3, 2018).

Shares of Common Stock To Be Outstanding After This Offering

407,626,237 shares of our common stock assuming no exercise of the underwriters’ option to purchase additional shares of common stock.

Option to Purchase Additional Shares of Common Stock

We have granted to the underwriters an option to purchase, within 30 days of this prospectus supplement, up to 2,850,000 shares of our common stock.

Use of Proceeds

We estimate that the net proceeds to us from this offering will be approximately $ million, or approximately $ million if the underwriters exercise their option to purchase additional shares of our common stock in full, after deducting underwriting discounts and commissions and estimated offering expenses. We intend to use the net proceeds from this offering to fund capital expenditures, including a portion of our recently announced Elk Creek Pipeline Project and other growth projects, to pre-fund additional projects which are in the late stages of development and for general corporate purposes, which may include repaying a portion of our outstanding indebtedness.

Exchange Listing

Our common stock is listed on the NYSE under the symbol “OKE.”

Risk Factors

There are risks associated with this offering and our business. You should carefully consider the risk factors discussed under the heading “Risk Factors” on page S-5 of this prospectus supplement and beginning on page 7 of the accompanying base prospectus and the other risks identified in the documents incorporated by reference herein and therein before making a decision to purchase common stock in this offering.

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RISK FACTORS

An investment in our common stock involves risk. You should carefully read the risk factors set forth in our most recent Annual Report on Form 10-K, subsequent Quarterly Reports on Form 10-Q and those that are included in the accompanying base prospectus, together with all of the other information included in, or incorporated by reference into, this prospectus supplement and the accompanying base prospectus, when evaluating an investment in our common stock.

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USE OF PROCEEDS

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CAPITALIZATION

The following table sets forth our cash and cash equivalents and capitalization as of September 30, 2017, on:

•

a historical basis; and

•

an as adjusted basis to give effect to $ million of net proceeds from this offering of common stock, after deducting underwriting discounts and commissions and estimated offering expenses, and the application of the net proceeds from this offering as described under “Use of Proceeds” in this prospectus supplement, assuming no exercise of the underwriters’ option to purchase additional shares of common stock.

This table should be read in conjunction with our historical consolidated financial statements and the notes to those financial statements that are incorporated by reference into this prospectus supplement and the accompanying base prospectus. You should also read this table in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operation” in our Annual Report on Form 10-K for the year ended December 31, 2016 and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2017, which are incorporated by reference herein.


	September 30, 2017
	Historical			As Adjusted
	(Dollars in thousands, except share data)
Cash and cash equivalents⁽¹⁾	$	11,676		$

Total debt		9,518,167

ONEOK shareholders’ equity⁽¹⁾:
Preferred stock, $0.01 par value: issued 20,000 shares		—
Common stock, $0.01 par value: 1,200,000,000 shares authorized, actual and as adjusted; 415,913,504 shares issued, actual, and 434,913,504 shares issued, as adjusted; 381,285,028 shares outstanding, actual, and 400,285,028 shares outstanding, as adjusted		4,159
Paid-in capital		6,418,038
Accumulated and other comprehensive loss		(181,771	)
Treasury stock, at cost: 34,628,476 shares		(880,931	)
Noncontrolling interests in consolidated subsidiaries		156,888
Total equity		5,516,383

Total capitalization	$	15,034,550		$

⁽¹⁾	Does not reflect the issuance and sale of 7,252,730 shares of common stock since September 30, 2017 under our “at the market” equity program, which resulted in an aggregate amount of net proceeds of $383.9 million and other issuances under the Company’s equity plans.

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PRICE RANGE OF OUR COMMON STOCK

Our common stock is listed on the NYSE under the symbol “OKE.” The following table indicates the high and low closing prices of our common stock, as reported by the NYSE, and the dividends that we paid per share during the periods indicated.


	High		Low		Dividends Declared/ Paid
2016
First Quarter	$	30.82	$	19.62	$	0.615
Second Quarter		47.45		28.37		0.615
Third Quarter		51.39		42.99		0.615
Fourth Quarter		59.03		46.44		0.615
2017
First Quarter	$	58.83	$	52.20	$	0.615
Second Quarter		56.33		47.41		0.615
Third Quarter		56.88		50.36		0.745
Fourth Quarter		56.70		50.02		0.745

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MATERIAL U.S. FEDERAL TAX CONSIDERATIONS

FOR NON-U.S. HOLDERS OF OUR COMMON STOCK

The following is a summary of the material U.S. federal income and estate tax consequences of the ownership and disposition of our common stock that is being issued pursuant to this offering. This summary is limited to Non-U.S. Holders (as defined below) that hold our common stock as a capital asset (generally, property held for investment) for U.S. federal income tax purposes. This summary does not discuss all of the aspects of U.S. federal income and estate taxation that may be relevant to a Non-U.S. Holder in light of the Non-U.S. Holder’s particular investment or other circumstances. Accordingly, all prospective Non-U.S. Holders should consult their own tax advisors with respect to the U.S. federal, state, local and non-U.S. tax consequences of the ownership and disposition of our common stock.

This summary is based on provisions of the U.S. Internal Revenue Code of 1986, as amended (which we refer to as the “Code”), applicable U.S. Treasury regulations and administrative and judicial interpretations, all as in effect or in existence on the date of this prospectus. Subsequent developments in U.S. federal income or estate tax law, including changes in law or differing interpretations, which may be applied retroactively, could alter the U.S. federal income and estate tax consequences of owning and disposing of our common stock as described in this summary. There can be no assurance that the Internal Revenue Service (the “IRS”) will not take a contrary position with respect to one or more of the tax consequences described herein and we have not obtained, nor do we intend to obtain, a ruling from the IRS with respect to the U.S. federal income or estate tax consequences of the ownership or disposition of our common stock.

As used in this summary, the term “Non-U.S. Holder” means a beneficial owner of our common stock that is not, for U.S. federal income tax purposes:

•

an individual who is a citizen or resident of the United States;

•

a corporation (or other entity treated as a corporation) created or organized in or under the laws of the United States, any state thereof, or the District of Columbia;

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an entity or arrangement treated as a partnership;

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an estate whose income is includible in gross income for U.S. federal income tax purposes regardless of its source; or

•

a trust, if (1) a U.S. court is able to exercise primary supervision over the trust’s administration and one or more “United States persons” (within the meaning of the Code) has the authority to control all of the trust’s substantial decisions, or (2) the trust has a valid election in effect under applicable U.S. Treasury regulations to be treated as a United States person.

If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds our common stock, the tax treatment of a partner in such a partnership generally will depend upon the status of the partner, the activities of the partnership and certain determinations made at the partner level. Partnerships, and partners in partnerships, that hold our common stock should consult their own tax advisors as to the particular U.S. federal income and estate tax consequences of owning and disposing of our common stock that are applicable to them.

This summary does not consider any specific facts or circumstances that may apply to a Non-U.S. Holder and does not address any special tax rules that may apply to particular Non-U.S. Holders, such as:

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a Non-U.S. Holder that is a financial institution, insurance company, tax-exempt organization, pension plan, broker, dealer or trader in stocks, securities or currencies, U.S. expatriate, controlled foreign corporation or passive foreign investment company;

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a Non-U.S. Holder holding our common stock as part of a conversion, constructive sale, wash sale or other integrated transaction or a hedge, straddle or synthetic security;

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•

a Non-U.S. Holder that holds or receives our common stock pursuant to the exercise of any employee stock option or otherwise as compensation; or

•

a Non-U.S. Holder that at any time owns, directly, indirectly or constructively, 5% or more of our outstanding common stock.

In addition, this summary does not address any U.S. state or local, or non-U.S. or other tax consequences, or any U.S. federal income or estate tax consequences for beneficial owners of a Non-U.S. Holder, including shareholders of a controlled foreign corporation or passive foreign investment company that holds our common stock.

Each Non-U.S. Holder should consult its own tax advisor regarding the U.S. federal, state, local and non-U.S. income and other tax consequences of owning and disposing of our common stock.

Distributions on Our Common Stock

Distributions of cash or property (other than certain pro rata distributions of our common stock) with respect to our common stock generally will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. If a distribution exceeds our current and accumulated earnings and profits, the excess will be treated as a nontaxable return of capital to the extent of the Non-U.S. Holder’s adjusted tax basis in its common stock and will reduce (but not below zero) such Non-U.S. Holder’s adjusted tax basis in its common stock. Any remaining excess will be treated as gain from a disposition of our common stock subject to the tax treatment described below in “Dispositions of Our Common Stock.”

Distributions on our common stock that are treated as dividends, and that are not effectively connected with a Non-U.S. Holder’s conduct of a trade or business in the United States, generally will be subject to withholding of U.S. federal income tax at a rate of 30%. A Non-U.S. Holder may be eligible for a lower rate under an applicable income tax treaty between the United States and its jurisdiction of tax residence. In order to claim the benefit of an applicable income tax treaty, a Non-U.S. Holder will be required to provide to the applicable withholding agent a properly executed IRS Form W-8BEN or W-8BEN-E (or other applicable form) in accordance with the applicable certification and disclosure requirements. Special rules apply to partnerships and other pass-through entities and these certification and disclosure requirements also may apply to beneficial owners of partnerships and other pass-through entities that hold our common stock.

Distributions on our common stock that are treated as dividends, and that are effectively connected with a Non-U.S. Holder’s conduct of a trade or business in the United States will be taxed on a net income basis at the regular graduated rates and in the manner applicable to United States persons (unless the Non-U.S. Holder is eligible for and properly claims the benefit of an applicable income tax treaty and the dividends are not attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States, in which case the Non-U.S. Holder would be subject to U.S. federal withholding taxes as described above but may be eligible for a reduced rate under such applicable income tax treaty). Dividends that are effectively connected with a Non-U.S. Holder’s conduct of a trade or business in the United States will not be subject to the withholding of U.S. federal income tax discussed above if the Non-U.S. Holder provides to the applicable withholding agent a properly executed IRS Form W-8ECI (or other applicable form) in accordance with the applicable certification and disclosure requirements. A Non-U.S. Holder that is treated as a corporation for U.S. federal income tax purposes may also be subject to a “branch profits” tax at a 30% rate (or a lower rate if the Non-U.S. Holder is eligible for a lower rate under an applicable income tax treaty) on the Non-U.S. Holder’s earnings and profits (attributable to dividends on our common stock or otherwise) that are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States, subject to certain adjustments.

The certifications described above must be provided to the applicable withholding agent prior to the payment of dividends and generally must be updated periodically. A Non-U.S. Holder may obtain a refund or

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credit of any excess amounts withheld by timely filing an appropriate claim for a refund with the IRS. Non-U.S. Holders should consult their own tax advisors regarding their eligibility for benefits under a relevant income tax treaty and the manner of claiming such benefits.

The foregoing discussion is subject to the discussions below under “Backup Withholding and Information Reporting” and “FATCA Withholding.”

Dispositions of Our Common Stock

A Non-U.S. Holder generally will not be subject to U.S. federal income tax (including withholding thereof) on any gain recognized on any sales or other dispositions of our common stock unless:

•

the gain is effectively connected with the Non-U.S. Holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States); in this case, the gain will be subject to U.S. federal income tax on a net income basis at the regular graduated rates and in the manner applicable to United States persons (unless an applicable income tax treaty provides otherwise) and, if the Non-U.S. Holder is treated as a corporation for U.S. federal income tax purposes, the “branch profits tax” described above may also apply;

•

the Non-U.S. Holder is an individual who is present in the United States for more than 182 days in the taxable year of the disposition and meets certain other requirements; in this case, except as otherwise provided by an applicable income tax treaty, the gain, which may be offset by certain U.S. source capital losses, generally will be subject to a flat 30% U.S. federal income tax, even though the Non-U.S. Holder is not considered a resident of the United States under the Code; or

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we are or have been a “United States real property holding corporation” for U.S. federal income tax purposes at any time during the shorter of (i) the five-year period ending on the date of disposition and (ii) the period that the Non-U.S. Holder held our common stock.

Generally, a corporation is a “United States real property holding corporation” if the fair market value of its “United States real property interests” equals or exceeds 50% of the sum of the fair market value of its worldwide real property interests plus its other assets used or held for use in a trade or business. We believe that we currently are, and expect to remain for the foreseeable future, a United States real property holding corporation. Nonetheless, the tax relating to disposition of stock in a United States real property holding corporation generally will not apply to a Non-U.S. Holder whose holdings, direct, indirect and constructive, constituted 5% or less of our common stock at all times during the applicable period, provided that our common stock is “regularly traded on an established securities market” (as provided in applicable U.S. Treasury regulations) at any time during the calendar year in which the disposition occurs. We believe that our common stock is regularly traded on an established securities market, however, no assurance can be provided that our common stock will continue to be regularly traded on an established securities market for purposes of the rules described above. Non-U.S. Holders should consult their own tax advisors regarding the U.S. federal income tax consequences to them of owning stock of a corporation that is a United States real property holding corporation.

The foregoing discussion is subject to the discussions below under “Backup Withholding and Information Reporting” and “FATCA Withholding.”

Federal Estate Tax

Our common stock that is owned (or treated as owned) by an individual who is not a U.S. citizen or resident of the United States (as specially defined for U.S. federal estate tax purposes) at the time of death will be included in the individual’s gross estate for U.S. federal estate tax purposes, unless an applicable estate tax or other treaty provides otherwise and, therefore, may be subject to U.S. federal estate tax.

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Backup Withholding and Information Reporting

Backup withholding (currently at a rate of 28%) will not apply to payments of dividends on our common stock to a Non-U.S. Holder if the Non-U.S. Holder provides to the applicable withholding agent a properly executed IRS Form W-8BEN or W-8BEN-E (or other applicable form) certifying under penalties of perjury that the Non-U.S. Holder is not a United States person, or otherwise qualifies for an exemption. However, the applicable withholding agent generally will be required to report to the IRS and to such Non-U.S. Holder the amount of payments of dividends on our common stock and the amount of U.S. federal income tax, if any, withheld with respect to those payments. Copies of the information returns reporting such dividends and any withholding may also be made available to the tax authorities in the country in which the Non-U.S. Holder resides under the provisions of a treaty or agreement.

The gross proceeds from sales or other dispositions of our common stock may be subject, in certain circumstances discussed below, to U.S. backup withholding and information reporting. If a Non-U.S. Holder sells or otherwise disposes of our common stock outside the United States through a non-U.S. office of a non-U.S. broker and the disposition proceeds are paid to the Non-U.S. Holder outside the United States, then the U.S. backup withholding and information reporting requirements generally will not apply to that payment. However, U.S. information reporting, but not U.S. backup withholding, will apply to a payment of disposition proceeds, even if that payment is made outside the United States, if a Non-U.S. Holder sells our common stock through a non-U.S. office of a broker that is a United States person or has certain enumerated connections with the United States, unless the broker has documentary evidence in its files that the Non-U.S. Holder is not a United States person and certain other conditions are met or the Non-U.S. Holder otherwise qualifies for an exemption.

If a Non-U.S. Holder receives payments of the proceeds of a disposition of our common stock to or through a U.S. office of a broker, the payment will be subject to both U.S. backup withholding and information reporting unless the Non-U.S. Holder provides to the broker a properly executed IRS Form W-8BEN or W-8BEN-E (or other applicable form) certifying under penalties of perjury that the Non-U.S. Holder is not a United States person, or the Non-U.S. Holder otherwise qualifies for an exemption.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be credited against the Non-U.S. Holder’s U.S. federal income tax liability (which may result in the Non-U.S. Holder being entitled to a refund), provided that the required information is timely furnished to the IRS.

FATCA Withholding

The Foreign Account Tax Compliance Act and related Treasury guidance (commonly referred to as “FATCA”) impose U.S. federal withholding tax at a rate of 30% on payments to certain foreign entities of (i) U.S.-source dividends (including dividends paid on our common stock) and (ii) the gross proceeds from the sale or other disposition after December 31, 2018 of property that produces U.S.-source dividends (including sales or other dispositions of our common stock). This withholding tax applies to a foreign entity, whether acting as a beneficial owner or an intermediary, unless such foreign entity complies with (i) certain information reporting requirements regarding its U.S. account holders and its U.S. owners and (ii) certain withholding obligations regarding certain payments to its account holders and certain other persons. Accordingly, the entity through which a Non-U.S. Holder holds its common stock will affect the determination of whether such withholding is required. Non-U.S. Holders are encouraged to consult their tax advisors regarding FATCA.

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UNDERWRITING

Under the terms and subject to the conditions contained in an underwriting agreement dated January , 2018, we have agreed to sell to the underwriters named below, for whom Credit Suisse Securities (USA) LLC is acting as representative, the following respective numbers of shares of common stock:


Underwriter		Number of Shares
Credit Suisse Securities (USA) LLC

Total

The underwriting agreement provides that the underwriters are obligated, severally and not jointly, to purchase all the shares of common stock in the offering if any are purchased, other than those shares covered by the over-allotment option described below. The underwriting agreement also provides that if an underwriter defaults the purchase commitments of non-defaulting underwriters may be increased or the offering may be terminated.

We have agreed to indemnify the underwriters and certain of their controlling persons against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”), and to contribute to payments that the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the shares, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the shares, and other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officers’ certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

The underwriters may offer the shares from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale at prices relating to prevailing market prices or at negotiated prices. The underwriters may effect such transactions by selling shares to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or purchasers of shares for whom they may act as agents or to whom they may sell as principal. The difference between the price at which the underwriters purchase shares and the price at which the underwriters resell such shares may be deemed underwriting compensation.

Option to Purchase Additional Shares

We have granted to the underwriters a 30-day option to purchase on a pro rata basis up to 2,850,000 additional shares from us at the initial public offering price less the underwriting discounts and commissions. The option may be exercised only to cover any over-allotments of common stock.

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Commissions and Discounts

The following table summarizes the compensation and estimated expenses we will pay:

Per Share

Total

Without
Over-allotment

With
Over-allotment

Without
Over-allotment

With
Over-allotment

Underwriting Discounts and Commissions paid by us

Expenses payable by us

We estimate that our out of pocket expenses for this offering will be approximately $ .

No Sales of Similar Securities

We will not, subject to limited exceptions, without the prior written consent of Credit Suisse Securities (USA) LLC, offer, sell, contract to sell, pledge, or otherwise dispose of (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by us or any of our affiliates or any person in privity with us or any of our affiliates), directly or indirectly, including the filing (or participation in the filing) of a registration statement with the Commission in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), any equity or equity-linked securities or securities convertible into equity securities issued by us (other than the shares of our common stock offered hereby) or publicly announce an intention to effect any such transaction, until 60 days after the date of this prospectus supplement.

In connection with this offering, our directors and executive officers have agreed with the underwriters to enter into lock-up agreements, pursuant to which outstanding shares of our common stock owned by our directors and executive officers will be restricted from immediate resale in accordance with the terms of such lock-up agreements without the prior written consent of Credit Suisse Securities (USA) LLC. Under these agreements, subject to limited exceptions, our directors or executive officers may not dispose of, hedge or otherwise transfer the economic consequences of ownership of any shares of common stock or securities convertible into or exchangeable or exercisable for shares of common stock. These restrictions will be in effect for a period of 60 days after the date of this prospectus supplement. Certain transfers or dispositions can be made sooner, provided the transferee becomes bound to the terms of the lock-up.

NYSE Listing

The shares of common stock are listed on the NYSE subject to official notice of issuance, under the symbol “OKE.”

Stabilization

In connection with the offering the underwriters may engage in stabilizing transactions, over-allotment transactions, syndicate covering transactions and penalty bids in accordance with Regulation M under the Exchange Act.

•

Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum.

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•

Over-allotment involves sales by the underwriters of shares in excess of the number of shares the underwriters are obligated to purchase, which creates a syndicate short position. The short position may be either a covered short position or a naked short position. In a covered short position, the number of shares over-allotted by the underwriters is not greater than the number of shares that they may purchase in the over-allotment option. In a naked short position, the number of shares involved is greater than the number of shares in the over-allotment option. The underwriters may close out any covered short position by either exercising their over-allotment option and/or purchasing shares in the open market.

•

Syndicate covering transactions involve purchases of the common stock in the open market after the distribution has been completed in order to cover syndicate short positions. In determining the source of shares to close out the short position, the underwriters will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which they may purchase shares through the over-allotment option. If the underwriters sell more shares than could be covered by the over-allotment option, a naked short position, the position can only be closed out by buying shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there could be downward pressure on the price of the shares in the open market after pricing that could adversely affect investors who purchase in the offering.

•

Penalty bids permit the representative to reclaim a selling concession from a syndicate member when the common stock originally sold by the syndicate member is purchased in a stabilizing or syndicate covering transaction to cover syndicate short positions.

•

In passive market making, market makers in the common stock who are underwriters or prospective underwriters may, subject to limitations, make bids for or purchases of our common stock until the time, if any, at which a stabilizing bid is made.

These stabilizing transactions, syndicate covering transactions and penalty bids may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of the common stock. As a result the price of our common stock may be higher than the price that might otherwise exist in the open market. These transactions may be effected on the NYSE or otherwise and, if commenced, may be discontinued at any time.

Electronic Distribution

A prospectus in electronic format may be made available on the websites maintained by one or more of the underwriters, if any, participating in this offering and one or more of the underwriters participating in this offering may distribute prospectuses electronically. The representative may agree to allocate a number of shares to underwriters for sale to their online brokerage account holders. Internet distributions will be allocated by the underwriters and selling group members that will make internet distributions on the same basis as other allocations.

Notice to Prospective Investors in the European Economic Area

In relation to each member state of the European Economic Area with effect from and including the date on which the Prospectus Directive is implemented in that relevant member state (the relevant implementation date), an offer of shares described in this prospectus supplement may not be made to the public in that relevant member state other than:

•

to any legal entity which is a qualified investor as defined in the Prospectus Directive;

•

to fewer than 150 natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the relevant Dealer or Dealers nominated by us for any such offer; or

•

in any other circumstances falling within Article 3(2) of the Prospectus Directive;

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provided that no such offer of securities shall require us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Directive.

For purposes of this provision, the expression an “offer of securities to the public” in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and the securities to be offered so as to enable an investor to decide to purchase or subscribe for the securities, as the expression may be varied in that member state by any measure implementing the Prospectus Directive in that member state, and the expression “Prospectus Directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive) and includes any relevant implementing measure in each relevant member state. The expression 2010 PD Amending Directive means Directive 2010/73/EU.

Each person in a Relevant Member State who receives any communication in respect of, or who acquires any of, the shares contemplated by this prospectus supplement and the accompanying prospectus will be deemed to have represented, warranted and agreed to and with each underwriter and ourselves that:

(a) it is a qualified investor within the meaning of the law in that Relevant Member State implementing Article 2(1)(e) of the Prospectus Directive; and

(b) in the case of any shares acquired by it as a financial intermediary, as that term is used in Article 3(2) of the Prospectus Directive, (i) the shares acquired by it in the offer have not been acquired on behalf of, nor have they been acquired with a view to their offer or resale to, persons in any Relevant Member State other than qualified investors, as that term is defined in the Prospectus Directive, or in circumstances in which the prior consent of the underwriters has been given to the offer or resale; or (ii) where shares have been acquired by it on behalf of persons in any Relevant Member State other than qualified investors under the Prospectus Directive, no offer will have been made to such persons.

Notice to Prospective Investors in the United Kingdom

This prospectus supplement and the accompanying prospectus are only being distributed to, and is only directed at, persons in the United Kingdom that are qualified investors within the meaning of Article 2(1)(e) of the Prospectus Directive that are also (i) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the “Order”) or (ii) high net worth entities, and other persons to whom it may lawfully be communicated, falling within Article 49(2)(a) to (d) of the Order (each such person being referred to as a “relevant person”). This prospectus supplement and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other persons in the United Kingdom. Any person in the United Kingdom that is not a relevant person should not act or rely on this document or any of its contents.

Notice to Prospective Investors in Canada

The shares may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the shares must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement and the accompanying prospectus (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

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Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Notice to Prospective Investors in France

Neither this prospectus supplement nor any other offering material relating to the shares described in this prospectus supplement has been submitted to the clearance procedures of the Autorité des Marchés Financiers or of the competent authority of another member state of the European Economic Area and notified to the Autorité des Marchés Financiers. The shares have not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus supplement nor any other offering material relating to the shares has been or will be:

•

released, issued, distributed or caused to be released, issued or distributed to the public in France; or

•

used in connection with any offer for subscription or sale of the shares to the public in France.

Such offers, sales and distributions will be made in France only:

•

to qualified investors (investisseurs qualifiés) and/or to a restricted circle of investors (cercle restraint d’investisseurs), in each case investing for their own account, all as defined in, and in accordance with, articles L.411-2, D.411-1, D.411-2, D.734-1, D.744-1, D.754-1 and D.764-1 of the French Code monétaire et financier;

•

to investment services providers authorized to engage in portfolio management on behalf of third parties; or

•

in a transaction that, in accordance with article L.411-2-II-1°-or-2°-or 3° of the French Code monétaire et financier and article 211-2 of the General Regulations (Règlement Général) of the Autorité des Marchés Financiers, does not constitute a public offer (appel public à l’épargne).

The shares may be resold directly or indirectly, only in compliance with articles L.411-1, L.411-2, L.412-1 and L.621-8 through L.621-8-3 of the French Code monétaire et financier.

Notice to Prospective Investors in Australia

No prospectus or other disclosure document (as defined in the Corporations Act 2001 (Cth) of Australia (the “Corporations Act”)) in relation to the shares has been or will be lodged with the Australian Securities & Investments Commission (“ASIC”). This document has not been lodged with ASIC and is only directed to certain categories of exempt persons. Accordingly, if you receive this document in Australia:

(a)

you confirm and warrant that you are either:

(i) a “sophisticated investor” under section 708(8)(a) or (b) of the Corporations Act;

(ii) a “sophisticated investor” under section 708(8)(c) or (d) of the Corporations Act and that you have provided an accountant’s certificate to us which complies with the requirements of section 708(8)(c)(i) or (ii) of the Corporations Act and related regulations before the offer has been made;

(iii) a person associated with the company under section 708(12) of the Corporations Act; or

(iv) a “professional investor” within the meaning of section 708(11)(a) or (b) of the Corporations Act, and to the extent that you are unable to confirm or warrant that you are an exempt sophisticated investor, associated person or professional investor under the Corporations Act any offer made to you under this document is void and incapable of acceptance; and

(b)

you warrant and agree that you will not offer any of the shares for resale in Australia within 12 months of the shares being issued unless any such resale offer is exempt from the requirement to issue a disclosure document under section 708 of the Corporations Act.

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Notice to Prospective Investors in Chile

The shares are not registered in the Securities Registry (Registro de Valores) or subject to the control of the Chilean Securities and Exchange Commission (Superintendencia de Valores y Seguros de Chile). This prospectus supplement and other offering materials relating to the offer of the shares do not constitute a public offer of, or an invitation to subscribe for or purchase, the shares in the Republic of Chile, other than to individually identified purchasers pursuant to a private offering within the meaning of Article 4 of the Chilean Securities Market Act (Ley de Mercado de Valores) (an offer that is not “addressed to the public at large or to a certain sector or specific group of the public”).

Notice to Prospective Investors in Hong Kong

The shares may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance(Cap. 32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong) and no advertisement, invitation or document relating to the shares may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to shares which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

Notice to Prospective Investors in Japan

The shares offered in this prospectus supplement have not been and will not be registered under the Financial Instruments and Exchange Law of Japan. The shares have not been offered or sold and will not be offered or sold, directly or indirectly, in Japan or to or for the account of any resident of Japan (including any corporation or other entity organized under the laws of Japan), except (i) pursuant to an exemption from the registration requirements of the Financial Instruments and Exchange Law and (ii) in compliance with any other applicable requirements of Japanese law.

Notice to Prospective Investors in Singapore

This prospectus supplement has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to compliance with conditions set forth in the SFA.

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

•

a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

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•

a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor,

shares, debentures and units of shares and debentures of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the shares pursuant to an offer made under Section 275 of the SFA except:

•

to an institutional investor (for corporations, under Section 274 of the SFA) or to a relevant person defined in Section 275(2) of the SFA, or to any person pursuant to an offer that is made on terms that such shares, debentures and units of shares and debentures of that corporation or such rights and interest in that trust are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction, whether such amount is to be paid for in cash or by exchange of securities or other assets, and further for corporations, in accordance with the conditions specified in Section 275 of the SFA;

•

where no consideration is or will be given for the transfer; or

•

where the transfer is by operation of law.

Underwriters’ Conflicts of Interest

The underwriters and their respective affiliates are full-service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Certain of the underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for us, for which they received or will receive customary fees and expenses. Affiliates of certain of the underwriters are also lenders under our revolving credit agreement and term loan agreement.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. These investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

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LEGAL MATTERS

The validity of the common stock being offered hereunder is being passed upon for us by GableGotwals, Tulsa, Oklahoma. Certain other legal matters for us will be passed upon for us by Fried, Frank, Harris, Shriver & Jacobson LLP, New York, New York. The underwriters will be represented by Shearman & Sterling LLP, New York, New York.

EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) incorporated in this prospectus supplement by reference to our Current Report on Form 8-K dated July 6, 2017 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Some of the statements contained in, or incorporated into, this prospectus supplement and the accompanying base prospectus are forward-looking statements as defined under federal securities laws. The forward-looking statements relate to our anticipated financial performance (including the projects described in “Summary—Recent Developments—The Elk Creek Pipeline Project” and the projected net income, capital expenditures, cash flow and projected levels of dividends), liquidity, management’s plans and objectives for our future growth projects and other future operations (including plans to construct additional natural gas and natural gas liquids facilities and related cost estimates), our business prospects, the outcome of regulatory and legal proceedings, market conditions and other matters. We make these forward-looking statements in reliance on the safe harbor protections provided under federal securities legislation and other applicable laws. The following discussion is intended to identify important factors that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

Forward-looking statements include the items identified in the preceding paragraph, the information concerning possible or assumed future results of our operations and other statements contained or incorporated by reference into this prospectus supplement or the accompanying base prospectus identified by words such as “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “should,” “goal,” “forecast,” “guidance,” “could,” “may,” “continue,” “might,” “potential,” “scheduled” and other words and terms of similar meaning.

You should not place undue reliance on the forward-looking statements. Known and unknown risks, uncertainties and other factors may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Those factors may affect our operations, markets, products, services and prices. In addition to any assumptions and other factors referred to specifically in connection with the forward-looking statements, factors that could cause our actual results to differ materially from those contemplated in any forward-looking statement include, among others, the following:

•

potential changes in market conditions;

•

the risk that cost savings, tax benefits and any other synergies from the Merger Transaction may not be fully realized or may take longer to realize than expected;

•

the impact and outcome of pending and future litigation, including litigation, if any, relating to the Merger Transaction;

•

the effects of weather and other natural phenomena, including climate change, on our operations, demand for our services and energy prices;

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•

competition from other U.S. and foreign energy suppliers and transporters, as well as alternative forms of energy, including, but not limited to, solar power, wind power, geothermal energy and biofuels such as ethanol and biodiesel;

•

the capital intensive nature of our businesses;

•

the profitability of assets or businesses acquired or constructed by us;

•

our ability to make cost-saving changes in operations;

•

risks of marketing, trading and hedging activities, including the risks of changes in energy prices or the financial condition of our counterparties;

•

the uncertainty of estimates, including accruals and costs of environmental remediation;

•

the timing and extent of changes in energy commodity prices;

•

the effects of changes in governmental policies and regulatory actions, including changes with respect to income and other taxes, pipeline safety, environmental compliance, climate change initiatives and authorized rates of recovery of natural gas and natural gas transportation costs;

•

the impact on drilling and production by factors beyond our control, including the demand for natural gas and crude oil; producers’ desire and ability to obtain necessary permits; reserve performance; and capacity constraints on the pipelines that transport crude oil, natural gas and NGLs from producing areas and our facilities;

•

difficulties or delays experienced by trucks, railroads or pipelines in delivering products to or from our terminals or pipelines;

•

changes in demand for the use of natural gas, NGLs and crude oil because of market conditions caused by concerns about climate change;

•

the impact of unforeseen changes in interest rates, debt and equity markets, inflation rates, economic recession and other external factors over which we have no control, including the effect on pension and postretirement expense and funding resulting from changes in equity and bond market returns;

•

our indebtedness, including guarantees, could make us vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and/or place us at competitive disadvantages compared with our competitors that have less debt, or have other adverse consequences;

•

actions by rating agencies concerning the credit ratings of our debt;

•

the results of administrative proceedings and litigation, regulatory actions, rule changes and receipt of expected clearances involving any local, state or federal regulatory body, including the Federal Energy Regulatory Commission (the “FERC”), the National Transportation Safety Board, the Pipeline and Hazardous Materials Safety Administration, the U.S. Environmental Protection Agency and the U.S. Commodity Futures Trading Commission;

•

our ability to access capital at competitive rates or on terms acceptable to us;

•

risks associated with adequate supply to our gathering, processing, fractionation and pipeline facilities, including production declines that outpace new drilling or extended periods of ethane rejection;

•

the risk that material weaknesses or significant deficiencies in our internal controls over financial reporting could emerge or that minor problems could become significant;

•

the impact and outcome of pending and future litigation;

•

the ability to market pipeline capacity on favorable terms, including the effects of:

•

future demand for and prices of natural gas, NGLs and crude oil;

•

competitive conditions in the overall energy market;

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•

availability of supplies of Canadian and U.S. natural gas and crude oil; and

•

availability of additional storage capacity;

•

performance of contractual obligations by our customers, service providers, contractors and shippers;

•

the timely receipt of approval by applicable governmental entities for construction and operation of our pipeline and other projects and required regulatory clearances;

•

our ability to acquire all necessary permits, consents or other approvals in a timely manner, to promptly obtain all necessary materials and supplies required for construction, and to construct gathering, processing, storage, fractionation and transportation facilities without labor or contractor problems;

•

the mechanical integrity of facilities operated;

•

demand for our services in the proximity of our facilities;

•

our ability to control operating costs;

•

acts of nature, sabotage, terrorism or other similar acts that cause damage to our facilities or our suppliers’ or shippers’ facilities;

•

economic climate and growth in the geographic areas in which we do business;

•

the risk of a prolonged slowdown in growth or decline in the U.S. or international economies, including liquidity risks in U.S. or foreign credit markets;

•

the impact of recently issued and future accounting updates and other changes in accounting policies;

•

the possibility of future terrorist attacks or the possibility or occurrence of an outbreak of, or changes in, hostilities or changes in the political conditions in the Middle East and elsewhere;

•

the risk of increased costs for insurance premiums, security or other items as a consequence of terrorist attacks;

•

risks associated with pending or possible acquisitions and dispositions, including our ability to finance or integrate any such acquisitions and any regulatory delay or conditions imposed by regulatory bodies in connection with any such acquisitions and dispositions;

•

the impact of uncontracted capacity in our assets being greater or less than expected;

•

the ability to recover operating costs and amounts equivalent to income taxes, costs of property, plant and equipment and regulatory assets in our state and FERC-regulated rates;

•

the composition and quality of the natural gas and NGLs we gather and process in our plants and transport on our pipelines;

•

the efficiency of our plants in processing natural gas and extracting and fractionating NGLs;

•

the impact of potential impairment charges;

•

the risk inherent in the use of information systems in our respective businesses, implementation of new software and hardware, and the impact on the timeliness of information for financial reporting;

•

our ability to control construction costs and completion schedules of our pipelines and other projects; and

•

the risk factors listed in the reports we have filed and may file with the Securities and Exchange Commission (the “SEC”), which are incorporated by reference into this prospectus supplement and the accompanying base prospectus.

These factors are not necessarily all of the important factors that could cause actual results to differ materially from those expressed in any of our forward-looking statements. Other factors could also have material

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adverse effects on our future results. These and other risks are described in greater detail under the caption “Risk Factors” in this prospectus supplement, the accompanying base prospectus, our Annual Report on Form 10-K for the fiscal year ended December 31, 2016 and in our other filings that we make with the SEC, which are available via the SEC’s website at www.sec.gov and our website at www.oneok.com. Information contained in our website does not constitute part of this prospectus supplement or the accompanying base prospectus. All forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these factors. Any such forward-looking statement speaks only as of the date on which such statement is made, and other than as required under securities laws, we undertake no obligation to update publicly any forward-looking statement whether as a result of new information, subsequent events or change in circumstances, expectations or otherwise.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and other reports and other information with the SEC under the Exchange Act. You may read and copy any materials we file with the SEC at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-732-0330. The SEC maintains an Internet site (http://www.sec.gov) that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC. Our SEC filings also are available on the SEC’s website. You also can obtain information about us at the offices of the NYSE, located at 11 Water Street, New York, New York 10005.

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INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” information into this prospectus supplement. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede the previously filed information. We incorporate by reference the documents listed below and any future filings made by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, other than any portions of the respective filings that were furnished, pursuant to Item 2.02 or Item 7.01 of Current Reports on Form 8-K (including exhibits related thereto) or other applicable SEC rules, rather than filed, prior to the consummation of the offering under this prospectus supplement:

•

Annual Report on Form 10-K (File No. 1-13643) for the year ended December 31, 2016, filed on February 28, 2017 (Item 8 superseded by Exhibit 99.1 to the Current Report on Form 8-K filed on July 6, 2017);

•

Quarterly Reports on Form 10-Q (File No. 1-13643) for the period ended March 31, 2017, filed on May 3, 2017; for the period ended June 30, 2017, filed on August 2, 2017 and for the period ended September 30, 2017, filed on November 1, 2017;

•

Current Reports on Form 8-K (File No. 1-13643) filed on January 19, 2017 (Item 8.01), February 1, 2017 (only the first report filed on this date) (Item 1.01/9.01 (other than Exhibits 99.1 and 99.2)), February 22, 2017 (Item 5.03/9.01), February 24, 2017 (Item 8.01/9.01), April 19, 2017 (Item 1.01/9.01 (other than Exhibit 99.1)), April 20, 2017 (Item 3.02/3.03/5.03/9.01), April 21, 2017 (Item 8.01), May 2, 2017 (only the first report filed on this date) (Item 5.02), May 26, 2017 (only Item 5.07 for the first report filed on this date and Item 5.02 for the second report filed on this date), June 23, 2017 (Item 8.01/9.01), June 28, 2017 (Item 1.02), July 3, 2017 (Item 1.01/2.01/2.03/5.03/5.07/9.01 (other than Exhibit 99.1)), July 6, 2017 (Item 8.01/9.01), July 13, 2017 (only Item 1.01/2.03/9.01 (other than Exhibit 99.1) for the first report filed on this date), July 19, 2017 (Item 8.01/9.01 for the first report filed on this date and Item 1.01/9.01 for the second report filed on this date), July 27, 2017 (Item 8.01), and October 26, 2017 (Item 8.01); and

•

the description of our common stock contained in our Form 8-A registration statement filed with the SEC on November 21, 1997, including any amendment or report filed for the purpose of updating that description.

If information in incorporated documents conflicts with information in this prospectus supplement, you should rely on the most recent information. If information in an incorporated document conflicts with information in another incorporated document, you should rely on the most recent incorporated document.

Documents incorporated by reference are available from us without charge, excluding any exhibits to those documents unless the exhibit is specifically incorporated by reference as an exhibit in this document. You can obtain documents incorporated by reference in this document by requesting them in writing or by telephone at the following address and phone number:

ONEOK, Inc.

100 West Fifth Street

Tulsa, Oklahoma 74103

Attention: Corporate Secretary

Telephone: (918) 588-7000

S-24

We have not authorized anyone to provide you with information other than the information contained or incorporated by reference in this prospectus supplement or the accompanying base prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell, or soliciting an offer to buy, securities in any jurisdiction where the offer and sale is not permitted. You should assume that the information appearing or incorporated by reference in this prospectus supplement, the accompanying base prospectus or any applicable pricing supplement is accurate only as of the date of the documents containing the information, regardless of the time of its delivery or of any sale of our securities. Our business, financial condition, results of operations and prospects may have changed since those dates.

S-25

LOGO

Debt Securities, Common Stock, Stock Purchase Contracts,

Stock Purchase Contract Units, Preferred Stock, Depositary Shares, and Warrants

Guarantee of Debt Securities of ONEOK, Inc. by ONEOK Partners, L.P. and by ONEOK Partners Intermediate Limited Partnership

We may offer and sell, from time to time in one or more issuances, (1) one or more series of debt securities, which may be senior or subordinated notes or debentures, or other senior or subordinated evidences of indebtedness, which may be fully and unconditionally guaranteed by ONEOK Partners, L.P. and by ONEOK Partners Intermediate Limited Partnership and which may include terms permitting or requiring holders to convert or exchange their debt securities for common stock, preferred stock or other securities, (2) shares of our common stock, (3) stock purchase contracts, (4) stock purchase contract units that consist of (a) a stock purchase contract and (b) senior or subordinated debt securities, or preferred stock, U.S. Treasury securities or other debt obligations of third parties, that may be used to secure the holders’ obligations under a purchase contract, (5) shares of our preferred stock, which may include terms permitting or requiring holders to convert or exchange their preferred stock for common stock or other securities, (6) depositary shares, or (7) warrants.

We will provide you with the specific terms of the particular securities being offered in supplements to this prospectus. Any prospectus supplement may also add, update, or change information contained in this prospectus. You should read this prospectus and each related prospectus supplement carefully before you make an investment decision. This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

Our common stock, par value $0.01 per share, is listed on the New York Stock Exchange under the symbol “OKE.”

Investing in these securities involves certain risks. Please read “Risk Factors” on page 7 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this Prospectus is July 6, 2017.

TABLE OF CONTENTS


	Page
ABOUT THIS PROSPECTUS		1

WHERE YOU CAN FIND MORE INFORMATION		1

INCORPORATION BY REFERENCE		2

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS		3

ABOUT ONEOK		6

RISK FACTORS		7

USE OF PROCEEDS		8

RATIO OF EARNINGS TO FIXED CHARGES		9

DESCRIPTION OF DEBT SECURITIES		10

DESCRIPTION OF GUARANTEE OF DEBT SECURITIES		22

DESCRIPTION OF CAPITAL STOCK		23

DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE CONTRACT UNITS		29

DESCRIPTION OF DEPOSITARY SHARES		30

DESCRIPTION OF WARRANTS		32

PLAN OF DISTRIBUTION		33

LEGAL MATTERS		35

EXPERTS		35

ABOUT THIS PROSPECTUS

The information contained in this prospectus is not complete and may be changed. We have not authorized anyone else to provide you with information other than the information provided in or incorporated by reference in this prospectus, any prospectus supplement, or documents to which we otherwise refer you. We are not making an offer of any securities in any jurisdiction where the offer is not permitted. You should not assume that the information in this prospectus, any prospectus supplement or any document incorporated by reference is accurate as of any date other than the date of the document in which such information is contained or such other date referred to in such document, regardless of the time of any sale or issuance of a security.

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission, or the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may sell different types of securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering and the securities offered by us in that offering. The prospectus supplement may also add, update or change information in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the headings “Where You Can Find More Information” and “Incorporation by Reference.”

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by reference to the actual documents. Copies of some of the documents referred to herein have been filed or will be filed or incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below in the section entitled “Where You Can Find More Information.”

Unless we otherwise indicate or unless the context requires, all references in this prospectus to:

•

“ONEOK,” “we,” “our,” “us” or similar references mean ONEOK, Inc. and its subsidiaries, predecessors and acquired businesses;

•

“common stock” mean our common stock, par value $0.01 per share;

•

“preferred stock” means our preferred stock, par value $0.01 per share; and

•

“securities” mean the debt securities, common stock, stock purchase contracts, stock purchase contract units, preferred stock, depositary shares and warrants described in this prospectus.

WHERE YOU CAN FIND MORE INFORMATION

We have filed a registration statement on Form S-3 with the SEC under the Securities Act of 1933, as amended, or the Securities Act, that registers the securities offered by this prospectus. The registration statement, including the attached exhibits, contains additional relevant information about us. The rules and regulations of the SEC allow us to omit some information included in the registration statement from this prospectus.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You can read and copy any materials we file with the SEC at its Public Reference Room at 100 F Street, NE, Room 1580, Washington, D.C. 20549. You can obtain information about the operations of the SEC Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC also maintains a website that contains information we file electronically with the SEC, which you can access over the Internet at http://www.sec.gov. Our common stock is listed on the New York Stock Exchange (NYSE: OKE), and you can obtain information about us at the offices of the New York Stock Exchange, 11 Wall Street, New York, New York 10005. General information about us, including our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to those reports, is available free of charge through our website at http://www.oneok.com as

soon as reasonably practicable after we electronically file them with, or furnish them to, the SEC. Information on, or accessible through, our website is not incorporated into this prospectus or our other securities filings and is not a part of these filings.

INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information we have filed with the SEC. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be part of this prospectus, and information that we file later with the SEC will automatically update and supersede the previously filed information.

The documents listed below and any future filings made by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, other than any portions of the respective filings that were furnished, pursuant to Item 2.02 or Item 7.01 of Current Reports on Form 8-K (including exhibits related thereto) or other applicable SEC rules, rather than filed, prior to the termination of the offerings under this prospectus are incorporated by reference in this prospectus:

•

Annual Report on Form 10-K (File No. 1-13643) for the year ended December 31, 2016, filed on February 28, 2017;

•

Quarterly Report on Form 10-Q (File No. 1-13643) for the period ended March 31, 2017, filed on May 3, 2017;

•

Current Reports on Form 8-K (File No. 1-13643) filed on January 19, 2017 (Item 8.01), February 1, 2017 (only the first report filed on this date) (Items 1.01/9.01 (other than Exhibits 99.1 and 99.2)), February 22, 2017 (Items 5.03/9.01), February 24, 2017 (Items 8.01/9.01), April 19, 2017 (Items 1.01/9.01, other than Exhibit 99.1), April 20, 2017 (Items 3.02/3.03/5.03/9.01), April 21, 2017 (Item 8.01), May 2, 2017 (only Item 5.02 for the first report filed on this date), May 26, 2017 (only Item 5.07 for the first report filed on this date and Item 5.02 for the second report filed on this date), June 23, 2017 (Items 8.01/9.01), June 28, 2017 (Item 1.02), July 3, 2017 (Items 1.01/2.01/2.03/5.03/5.07/9.01 (other than Exhibit 99.1)) and July 6, 2017 (Items 8.01 and 9.01); and

•

You may request a copy of these filings (other than an exhibit to the filings unless we have specifically

incorporated that exhibit by reference into the filing), at no cost, by writing or telephoning us at the following address:

ONEOK, Inc.

100 West Fifth Street

Tulsa, Oklahoma 74103

Attention: Corporate Secretary

Telephone: (918) 588-7000

We have not authorized anyone to provide you with information other than the information contained or incorporated by reference in this prospectus or in any prospectus supplement. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell, or soliciting an offer to buy, securities in any jurisdiction where the offer and sale is not permitted. You should assume that the information appearing or incorporated by reference in this prospectus, the applicable prospectus supplement or any applicable pricing supplement is accurate only as of the date of the documents containing the information, regardless of the time of its delivery or of any sale of our securities. Our business, financial condition, results of operations and prospects may have changed since those dates.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Some of the statements contained and incorporated in this prospectus are forward-looking statements as defined under federal securities laws. The forward-looking statements relate to our anticipated financial performance (including projected net income, capital expenditures, cash flow and projected levels of dividends), liquidity, management’s plans and objectives for our future growth projects and other future operations (including plans to construct additional natural gas and natural gas liquids facilities and related cost estimates), our business prospects, the outcome of regulatory and legal proceedings, market conditions and other matters. We make these forward-looking statements in reliance on the safe harbor protections provided under federal securities legislation and other applicable laws. The following discussion is intended to identify important factors that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

Forward-looking statements include the items identified in the preceding paragraph, the information concerning possible or assumed future results of our operations and other statements contained or incorporated in this prospectus or the accompanying prospectus supplement identified by words such as “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “should,” “goal,” “forecast,” “guidance,” “could,” “may,” “continue,” “might,” “potential,” “scheduled” and other words and terms of similar meaning.

•

the effects of weather and other natural phenomena, including climate change, on our operations, demand for our services and energy prices;

•

competition from other United States and foreign energy suppliers and transporters, as well as alternative forms of energy, including, but not limited to, solar power, wind power, geothermal energy and biofuels such as ethanol and biodiesel;

•

the capital intensive nature of our businesses;

•

the profitability of assets or businesses acquired or constructed by us;

•

our ability to make cost-saving changes in operations;

•

risks of marketing, trading and hedging activities, including the risks of changes in energy prices or the financial condition of our counterparties;

•

the uncertainty of estimates, including accruals and costs of environmental remediation;

•

the timing and extent of changes in energy commodity prices;

•

difficulties or delays experienced by trucks, railroads or pipelines in delivering products to or from our terminals or pipelines;

•

changes in demand for the use of natural gas, NGLs and crude oil because of market conditions caused by concerns about climate change;

•

our indebtedness could make us vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and/or place us at competitive disadvantages compared with our competitors that have less debt, or have other adverse consequences;

•

actions by rating agencies concerning the credit ratings of our debt;

•

the results of administrative proceedings and litigation, regulatory actions, rule changes and receipt of expected clearances involving any local, state or federal regulatory body, including the Federal Energy Regulatory Commission (“FERC”), the National Transportation Safety Board, the Pipeline and Hazardous Materials Safety Administration, the United States Environmental Protection Agency and the U.S. Commodity Futures Trading Commission;

•

our ability to access capital at competitive rates or on terms acceptable to us;

•

the risk that material weaknesses or significant deficiencies in our internal controls over financial reporting could emerge or that minor problems could become significant;

•

the impact and outcome of pending and future litigation;

•

the ability to market pipeline capacity on favorable terms, including the effects of:

•

future demand for and prices of natural gas, NGLs and crude oil;

•

competitive conditions in the overall energy market;

•

availability of supplies of Canadian and United States natural gas and crude oil; and

•

availability of additional storage capacity;

•

performance of contractual obligations by our customers, service providers, contractors and shippers;

•

the timely receipt of approval by applicable governmental entities for construction and operation of our pipeline and other projects and required regulatory clearances;

•

the mechanical integrity of facilities operated;

•

demand for our services in the proximity of our facilities;

•

our ability to control operating costs;

•

acts of nature, sabotage, terrorism or other similar acts that cause damage to our facilities or our suppliers’ or shippers’ facilities;

•

economic climate and growth in the geographic areas in which we do business;

•

the risk of a prolonged slowdown in growth or decline in the United States or international economies, including liquidity risks in United States or foreign credit markets;

•

the impact of recently issued and future accounting updates and other changes in accounting policies;

•

the possibility of future terrorist attacks or the possibility or occurrence of an outbreak of, or changes in, hostilities or changes in the political conditions in the Middle East and elsewhere;

•

the risk of increased costs for insurance premiums, security or other items as a consequence of terrorist attacks;

•

the impact of uncontracted capacity in our assets being greater or less than expected;

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the ability to recover operating costs and amounts equivalent to income taxes, costs of property, plant and equipment and regulatory assets in our state and FERC-regulated rates;

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the composition and quality of the natural gas and NGLs we gather and process in our plants and transport on our pipelines;

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the efficiency of our plants in processing natural gas and extracting and fractionating NGLs;

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the impact of potential impairment charges;

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the risk inherent in the use of information systems in our respective businesses, implementation of new software and hardware, and the impact on the timeliness of information for financial reporting;

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our ability to control construction costs and completion schedules of our pipelines and other projects; and

•

the risk factors listed in the reports we have filed and may file with the SEC, which are incorporated by reference.

These factors are not necessarily all of the important factors that could cause actual results to differ materially from those expressed in our forward-looking statements. Other factors could also have material adverse effects on our future results. These and other risks are described in greater detail in Part 1, Item 1A, Risk Factors, in our Annual Report on Form 10-K for the year ended December 31, 2016, and Part II, Item 1A, Risk Factors, in our Quarterly Report on Form 10-Q for the period ended March 31, 2017 and in our other filings that we make with the SEC, which are available via the SEC’s website at www.sec.gov and our website at www.oneok.com. All forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these factors. Any such forward-looking statement speaks only as of the date on which such statement is made, and other than as required under securities laws, we undertake no obligation to update publicly any forward-looking statement whether as a result of new information, subsequent events or change in circumstances, expectations or otherwise.

ABOUT ONEOK

We are a corporation incorporated under the laws of the state of Oklahoma, and our common stock is listed on the New York Stock Exchange under the trading symbol “OKE.” We apply our core capabilities of gathering, processing, fractionating, transporting, storing and marketing natural gas and NGLs through the rebundling of services across the value chains through vertical integration in an effort to provide our customers with premium services at lower costs. We are a leader in the gathering, processing, storage and transportation of natural gas in the United States. In addition, we own one of the nation’s premier natural gas liquids systems, connecting NGL supply in the Mid-Continent and Rocky Mountain regions and the Permian Basin with key market centers.

RISK FACTORS

Before you invest in our securities, you should carefully consider the following risk factor with those risk factors included in our most recent Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and our other filings with the SEC that are incorporated herein by reference and any prospectus supplement or free writing prospectus used in connection with an offering of our securities, as well as the information relating to us identified above under “Cautionary Statement Regarding Forward-Looking Statements.”

If any of the risks discussed below or in the foregoing documents were actually to occur, our business, financial condition, results of operations, or cash flow could be materially adversely affected. In that case, our ability to pay dividends to our shareholders or pay interest on, or the principal of, any debt securities, may be reduced, the trading price of our securities could decline and you could lose all or part of your investment.

Our consolidated debt and guarantee obligations could make us more vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and place us at a competitive disadvantage.

In connection with our acquisition of the common units of ONEOK Partners, L.P. that we did not previously own, ONEOK Partners, L.P. and ONEOK Partners Intermediate Limited Partnership entered into agreements guaranteeing our obligations under our $2.5 billion revolving credit agreement and our outstanding senior notes and commercial paper, and we entered into agreements guaranteeing ONEOK Partners’ obligations under its $1.0 billion term loan agreement and its outstanding senior notes. We are therefore liable for these debt obligations of ONEOK Partners, L.P. in the event of a default. Our indebtedness, along with our guarantee obligations, could make us more vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds, place us at competitive disadvantages compared with our competitors that have less debt and fewer guarantee obligations and/or have other adverse consequences.

USE OF PROCEEDS

Unless we inform you otherwise in an applicable prospectus supplement, ONEOK will use the net proceeds from the sale of the offered securities for general corporate purposes. These purposes may include repayment and refinancing of debt, acquisitions, working capital, capital expenditures and repurchases and redemptions of securities. Pending any specific application, we may initially invest funds in marketable securities or apply them to the reduction of short-term indebtedness.

RATIO OF EARNINGS TO FIXED CHARGES

Our ratio of earnings to fixed charges in each of the periods shown is as follows:

Three months ended March 31,

For the years ended December 31,

2017

2016

2015

2014

2013

2012

3.07x

2.99x

2.48x

3.18x

2.80x

3.39x

For purposes of computing the ratio of earnings to fixed charges, “earnings” consists of pretax income from continuing operations before adjustment for income or loss from equity investees plus fixed charges and distributed income of equity investees, less interest capitalized. “Fixed charges” consists of interest charges, the amortization of debt discounts and issue costs and the representative interest portion of operating leases.

DESCRIPTION OF DEBT SECURITIES

The following description states the general terms and provisions of our debt securities. The debt securities offered by this prospectus will be issued under one of two separate indentures among us, ONEOK Partners, L.P. and ONEOK Partners Intermediate Limited Partnership (together with ONEOK Partners, L.P., the “Guarantors”), and U.S. Bank National Association, as trustee. We have filed the forms of indenture as exhibits to the registration statement of which this prospectus is a part. The debt securities will be unsecured obligations of ONEOK and will be either senior or subordinated debt. Senior debt will be issued under a senior indenture and subordinated debt will be issued under a subordinated indenture. The senior indenture and the subordinated indenture are sometimes referred to in this prospectus individually as an “Indenture” and collectively as the “Indentures.” Each prospectus supplement that we provide when we offer debt securities will describe the specific terms of the debt securities offered through that prospectus supplement and any general terms outlined in this section that will not apply to those debt securities. Unless otherwise specified in this prospectus, the term “debt securities” includes senior debt securities and subordinated debt securities and the descriptions of the debt securities describe both the senior debt securities and the subordinated debt securities unless otherwise specified in this prospectus or any prospectus supplement.

We have summarized the material terms and provisions of the Indentures in this section. The summary is not complete. We have filed the forms of each of the Indentures as exhibits to the registration statement of which this prospectus forms a part. You should read the applicable form of Indenture for additional information before you buy any debt securities. Each of the Indentures is qualified under the Trust Indenture Act. You should refer to the Trust Indenture Act for provisions that apply to the debt securities. This summary also is subject to and qualified by reference to the description of the particular terms of the debt securities described in the applicable prospectus supplement or supplements and pricing supplement or supplements. Capitalized terms used but not defined in this summary have the meanings specified in the applicable Indenture. In this section, “we,” “us” and “our” refer only to ONEOK, Inc. and not to any of our subsidiaries.

Debt securities issued under either Indenture will be issued as part of a series that will be established pursuant to a supplemental indenture or other authorized corporate action designating the specific terms of the series of debt securities. A prospectus supplement will describe these terms and will include, among other things, the following:

•

the title of the debt securities of the particular series and whether the debt securities will be senior debt securities or subordinated debt securities;

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the total principal amount of those debt securities and the percentage of their principal amount at which we will issue those debt securities;

•

the date or dates on which the principal of those debt securities will be payable;

•

the interest rate, the method for determining the interest rate (if the interest rate is variable), the date from which interest will accrue, interest payment dates and record dates for interest payments;

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the place or places where payments on those debt securities will be made, where holders may surrender their debt securities for transfer or exchange and where to serve notices or demands;

•

any provisions for optional redemption or early repayment;

•

any provisions that would obligate us to redeem, purchase or repay those debt securities;

•

any provisions for conversion or exchange of the debt securities;

•

whether payments on the debt securities of the particular series will be payable by reference to any index, formula or other method;

•

any deletions from, changes of or additions to the events of default, covenants or other provisions described in this prospectus;

•

the portion of the principal amount of those debt securities that will be payable if the maturity is accelerated, if other than the entire principal amount;

•

any additional means of defeasance of all or any portion of those debt securities, any additional conditions or limitations to defeasance of those debt securities or any changes to those conditions or limitations;

•

any provisions granting special rights to holders of the debt securities of the particular series upon the occurrence of events identified in the prospectus supplement;

•

if other than the trustee, the designation of any paying agent or security registrar for those debt securities and the designation of any transfer or other agents or depositories for those debt securities;

•

whether we will issue the debt securities of the particular series in individual physical certificates to each holder or in the form of temporary or permanent global securities that a depository will hold on behalf of holders;

•

the denominations in which we will issue the debt securities of the particular series or in which they may be owned, if other than $1,000 or any integral multiple of $1,000;

•

whether the debt securities of such series will be guaranteed by the Guarantors pursuant to the guarantee provisions of the Indenture governing such series, any modifications to the terms of such provisions applicable to the debt securities of such series and the applicability of any other guarantees; and

•

any other terms or conditions that are consistent with such Indenture, which may include the applicability of or change in the subordination provisions of such Indenture or providing collateral, security or assurance for a series of debt securities.

We may sell the debt securities at a discount (which may be substantial) below their stated principal amount. These discounted debt securities may bear no interest or interest at a rate that at the time of issuance is below market rates. We will describe in the prospectus supplement any material United States federal income tax consequences and other special considerations.

Certain Restrictive Covenants Under Our Senior Indenture

Under the senior indenture, we have agreed to two principal restrictions on our activities for the benefit of holders of the senior debt securities. The restrictive covenants summarized below will apply to a series of senior debt securities (unless waived or amended) as long as any of those senior debt securities are outstanding or, unless the prospectus supplement for the series states otherwise. We have used in this summary description capitalized terms that we have defined below under “—Glossary.” Our Restricted Subsidiaries are those that own or lease a Principal Property.

Other than the restrictions on Liens and Sale/Leaseback transactions under the senior indenture described below, the Indentures and the debt securities do not contain any covenants or other provisions designed to protect holders of any debt securities in the event we participate in a highly leveraged transaction. The Indentures and the debt securities also do not contain provisions that give holders of the debt securities the right to require us to repurchase their securities in the event of change-in-control, recapitalization or similar restructuring or otherwise or upon a decline in our credit rating.

For these purposes, “debt” means obligations for money borrowed, evidenced by notes, bonds, debentures or other similar evidences of indebtedness.

Limitation on Liens

We agree that we will not, and will not permit any Restricted Subsidiary to, create, incur, issue or assume any debt secured by any Lien on any Principal Property, or on shares of stock or debt of any Restricted

Subsidiary, without making effective provision for the outstanding securities issued under the senior indenture (except as otherwise specified pursuant to an applicable supplemental indenture) to be secured by the Lien equally and ratably with (or prior to) any and all debt and obligations secured or to be secured thereby for so long as such debt is so secured, except that the foregoing restriction will not apply to:

•

Any Lien existing on the date of the first issue of securities under the senior indenture.

•

Any Lien on any Principal Property or Restricted Securities of any Person existing at the time such Person is merged or consolidated with or into us or a Restricted Subsidiary, or such Person becomes a Restricted Subsidiary.

•

Any Lien on any Principal Property existing at the time of acquisition of such Principal Property by us or a Restricted Subsidiary, whether or not assumed by us or such Restricted Subsidiary, provided that no such Lien may extend to any other Principal Property of ours or of any Restricted Subsidiary.

•

Any Lien on any Principal Property (including any improvements on an existing Principal Property) of ours or of any Restricted Subsidiary, and any Lien on the shares of stock of a Restricted Subsidiary that was formed or is held for the purpose of acquiring and holding such Principal Property, in each case to secure all or any part of the cost of acquisition, development, operation, construction, alteration, repair or improvement of all or any part of such Principal Property (or to secure Indebtedness incurred by us or a Restricted Subsidiary for the purpose of financing all or any part of such cost); provided that such Lien is created prior to, at the time of, or within 12 months after the latest of, the acquisition, completion of construction or improvement or commencement of commercial operation of such Principal Property and provided, further, that no such Lien may extend to any other Principal Property of us or any Restricted Subsidiary, other than any theretofore unimproved real property on which the Principal Property is so constructed or developed or the improvement is located.

•

Any Lien on any Principal Property or Restricted Securities to secure debt owing to us or to another Restricted Subsidiary.

•

Any Lien in favor of governmental bodies to secure advances or other payments pursuant to any contract or statute or to secure debt incurred to finance the purchase price or cost of constructing or improving the property subject to such Lien.

•

Any Lien created in connection with a project financed with, and created to secure, non-recourse indebtedness.

•

Carriers’, warehousemen’s, mechanics’, landlords’, materialmen’s, repairmen’s or other similar Liens arising in the ordinary course of business which are not delinquent or remain payable without penalty or which are being contested in good faith and by appropriate proceedings.

•

Liens (other than Liens imposed by Employee Retirement Income Security Act of 1974) on the property of ours or any of our Restricted Subsidiaries incurred, or pledges or deposits required, in connection with workmen’s compensation, unemployment insurance and other social security legislation.

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Liens securing taxes that remain payable without penalty or which are being contested in good faith by appropriate proceedings where collection thereof is stayed; provided that we have or any Restricted Subsidiary has set aside on its books reserves with respect to such taxes (segregated to the extent required by GAAP) deemed by it to be adequate.

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Any right which any municipal or governmental body or agency may have by virtue of any franchise, license or contract to purchase or designate a purchaser of, or order the sale of, any property of ours upon payment of reasonable compensation therefor or to terminate any franchise, license or other rights or to regulate our property and business.

•

Any Liens, neither assumed by us or any Restricted Subsidiary or on which we or any Restricted Subsidiary customarily pays interest, existing upon real estate or rights in or relating to real estate

acquired by us or any Restricted Subsidiary for sub-station, measuring station, regulating station, gas purification station, compressor station, transmission line, distribution line or right-of-way purposes.

•

Easements or reservations in any property of ours or of any Restricted Subsidiary for the purpose of roads, pipe lines, gas transmission and distribution lines, electric light and power transmission and distribution lines, water mains and other like purposes, and zoning ordinances, regulations and restrictions which do not impair the use of such property in the operation of the business of ours or of any Restricted Subsidiary.

•

Any extension, renewal, substitution or replacement (or successive extensions, renewals, substitutions or replacements), in whole or in part, of any Lien referred to in above, provided that the debt secured thereby may not exceed the principal amount of debt so secured at the time of such renewal or refunding, and that such renewal or refunding Lien must be limited to all or any part of the same property and improvements thereon, shares of stock or debt that secured the Lien renewed or refunded.

•

Any Lien not permitted above securing debt that, together with the aggregate outstanding principal amount of other secured debt that would otherwise be subject to the foregoing restrictions (excluding debt secured by Liens permitted under the foregoing exceptions) and the Attributable Debt in respect of all Sale and Leaseback Transactions (not including Attributable Debt in respect of any such Sale and Leaseback Transactions described in the third and fourth “bullet points” in “Limitations on Sale and Leaseback Transactions”) would not then exceed 15% of Consolidated Net Tangible Assets.

Limitation on Sale/Leaseback Transactions

We agree that we will not, and will not permit any Restricted Subsidiary to, enter into any Sale and Leaseback Transaction unless:

•

we or a Restricted Subsidiary would be entitled, without securing the outstanding securities under the senior indenture, to incur debt secured by a Lien on the Principal Property that is the subject of such Sale and Leaseback Transaction;

•

the Attributable Debt associated therewith would be in an amount permitted under the “basket” described above under “Limitation on Liens”;

•

the proceeds received in respect of the Principal Property so sold and leased back at the time of entering into such Sale and Leaseback Transaction are used for the business and operations of us or any subsidiary; or

•

within 12 months after the sale or transfer, an amount equal to the proceeds received in respect of the Principal Property so sold and leased back at the time of entering into such Sale and Leaseback Transaction is applied to the prepayment (other than mandatory prepayment) of any outstanding securities issued under the senior indenture or Funded Indebtedness of ours or of a Restricted Subsidiary (other than Funded Indebtedness that is held by us or any Restricted Subsidiary or Funded Indebtedness of ours that is subordinate in right of payment to any outstanding securities issued under the senior indenture).

Glossary

“Attributable Debt” means, as to any particular Sale and Leaseback Transaction under which any Person is at the time liable, at any date as of which the amount thereof is to be determined, the total net amount of rent required to be paid by that Person under the lease during the remaining term thereof (excluding amounts required to be paid on account of maintenance and repairs, services, insurance, taxes, assessments, water rates and similar charges and contingent rents), discounted from the respective due dates thereof at the weighted average of the rates of interest (or yield to maturity, in the case of senior debt securities originally sold at a discount) borne by the debt securities then outstanding under the senior indenture, compounded annually.

“Consolidated Net Tangible Assets” means the total amount of assets (less applicable reserves and other properly deductible items) that under generally accepted accounting principles, or GAAP, would be included on a consolidated balance sheet of ours and our subsidiaries after deducting therefrom (A) all current liabilities, provided, however, that there will not be deducted billings recorded as revenues deferred pending the outcome of rate proceedings (less applicable income taxes thereon), if and to the extent the obligation to refund the same has not been finally determined, (B) appropriate allowance for minority interests in common stocks of subsidiaries and (C) all goodwill, trade names, trademarks, patents, unamortized debt discount and expense and other like intangibles, which in each case under GAAP would be included on the consolidated balance sheet.

“Funded Indebtedness” as applied to any Person, means all debt of that Person maturing after, or renewable or extendable at that Person’s option beyond, 12 months from the date of determination.

“Lien” means any lien, mortgage, pledge, encumbrance, charge or security interest securing debt; provided, however, that the following types of transactions will not be considered for purposes of this definition to result in a Lien: (1) any acquisition by us or any of our Restricted Subsidiaries of any property or assets subject to any reservation or exception under the terms of which any vendor, lessor or assignor creates, reserves or excepts or has created, reserved or excepted an interest in oil, gas or any other mineral in place or the proceeds thereof, (2) any conveyance or assignment whereby we or any Restricted Subsidiary convey or assign to any Person or Persons an interest in oil, gas or any other mineral in place or the proceeds thereof, (3) any Lien upon any property or assets either owned or leased by us or any Restricted Subsidiary or in which we or any Restricted Subsidiary own an interest that secures for the benefit of the Person or Persons paying the expenses of developing or conducting operations for the recovery, storage, transportation or sale of the mineral resources of the property or assets (or property or assets with which it is unitized) the payment to that Person or Persons of our or a Restricted Subsidiary’s proportionate part of such development or operating expenses or (4) any hedging arrangements entered into in the ordinary course of business, including any obligation to deliver any mineral, commodity or asset in connection therewith.

“Person” means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization or government or any agency or political subdivision thereof.

“Principal Property” means any property located in the United States, except any property that in the opinion of our board of directors is not of material importance to the total business conducted by us and our consolidated subsidiaries.

“Restricted Securities” means shares of stock or debt of any Restricted Subsidiary.

“Restricted Subsidiary” means any subsidiary that owns or leases Principal Property.

“Sale/Leaseback Transaction” means any arrangement with any Person pursuant to which we or any Restricted Subsidiary lease any Principal Property that has been or is to be sold or transferred by us to that Person, other than (1) a lease for a term, including renewals at the option of the lessee, of not more than three years or classified as an operating lease under GAAP, (2) leases between us and a Restricted Subsidiary or between Restricted Subsidiaries, (3) leases of a Principal Property executed by the time of, or within 12 months after the latest of, the acquisition, the completion of construction or improvement, or the commencement of commercial operation, of the Principal Property and (4) the ground lease for ONEOK Plaza, 100 West Fifth Street, Tulsa, Oklahoma 74103.

Consolidation, Merger and Sale of Assets

The Indentures generally permit a consolidation or merger between us and another entity. They also permit the sale by us of all or substantially all of our assets. We have agreed, unless we inform you otherwise in the

prospectus supplement, however, that we will consolidate with or merge into any entity or transfer or dispose of all or substantially all of our assets to any entity only if:

•

immediately after giving effect to the transaction, no default or event of default under either of the Indentures would have occurred and be continuing or would result from the transaction;

•

we are the continuing corporation or, if we are not the continuing corporation, the resulting entity is organized and existing under the laws of any United States jurisdiction and assumes the due and punctual payments on the debt securities and the performance of our covenants and obligations under the Indenture and those debt securities; and

•

we provide the trustee with a certificate and a legal opinion, each stating that the applicable Indenture permits the transaction.

Under the senior indenture, if we engage in any of these transactions that result in any Principal Property or shares of stock or debt of any Restricted Subsidiary becoming subject to any Lien and unless we are otherwise able to create that Lien, the senior debt securities (so long as those senior debt securities are entitled to the protection of the “Limitation on Liens” covenant) will be secured to at least the same extent as the debt that would become secured by the Lien as a result of the transaction.

Events of Default

Unless we inform you otherwise in the prospectus supplement, the following are events of default for a series of debt securities:

•

our failure to pay interest on that series of debt securities for 30 days after it becomes due and payable;

•

our failure to pay principal of or any premium on that series of debt securities when due;

•

our failure to comply with any of our covenants or agreements for that series of debt securities or in the applicable Indenture (other than an agreement or covenant that we have included in such Indenture solely for the benefit of less than all series of debt securities) for 60 days after the trustee or the holders of at least 25% in principal amount of all outstanding debt securities affected by that failure provide written notice to us;

•

the default under any agreement under which we have or any Restricted Subsidiary has at the time outstanding debt in excess of $100,000,000 and, if that debt has not already matured, it has been accelerated and the acceleration is not rescinded within 30 days after we receive notice from the trustee or the holders of at least 25% in principal amount of all outstanding debt securities of a series so long as, prior to the entry of judgment in favor of the trustee for payment of the debt securities of that series, we do not cure the default, or the default under the agreement has not been waived;

•

various events involving our bankruptcy, insolvency or reorganization; or

•

any other event of default provided for that series of debt securities.

A default under one series of debt securities will not necessarily be a default under another series. The trustee may withhold notice to the holders of a series of debt securities of any default or event of default (except in any payment on that series of debt securities) if the trustee considers it in the interest of the holders of that series of debt securities to do so.

If an event of default for any series of debt securities occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of the series affected by the default (or, in some cases, 25% in principal amount of all debt securities affected, voting as one class) may require us to pay on an accelerated basis the principal of and all accrued and unpaid interest on those debt securities. The holders of a majority in principal amount of the outstanding debt securities of the series affected by the default (or of all debt securities affected, voting as one class) may in some cases rescind this accelerated payment requirement.

If an event of default occurs and is continuing, the trustee must use the degree of care and skill of a prudent man in the conduct of his own affairs. The trustee will become obligated to exercise any of its powers under the applicable Indenture at the request of any of the holders of any debt securities only after those holders have offered the trustee indemnity reasonably satisfactory to it.

The holders of a majority in principal amount of debt securities of any series have the right to waive past defaults under the applicable Indenture that relate to that series except for a default in the payment on the debt securities or a provision that can only, under the applicable Indenture, be modified or amended if all holders that are affected consent.

In most cases, holders of a majority in principal amount of the outstanding debt securities of a series (or of all debt securities affected, voting as one class) may direct the time, method and place of:

•

conducting any proceeding for any remedy available to the trustee; and

•

exercising any trust or power conferred on the trustee.

The Indentures require us to file each year with the trustee a written statement as to our compliance with the covenants contained in the Indentures.

Modification and Waiver

We and each guarantor (if any) may amend or supplement either of the Indentures if the holders of a majority in principal amount of the outstanding debt securities of all series that the amendment or supplement affects (acting as one class) consent to it. Without the consent of the holder of each debt security affected, however, no modification may:

•

reduce the principal of the debt security or change its stated maturity;

•

reduce the rate of or change the time for payment of interest on the debt security;

•

reduce any premium payable on the redemption of the debt security or change the time at which the debt security may or must be redeemed;

•

change any obligation to pay additional amounts on the debt security;

•

impair the holder’s right to institute suit for the enforcement of any payment on the debt security;

•

impair the holder’s right to convert or exchange any debt security;

•

reduce the percentage of principal amount of debt securities whose holders must consent to an amendment to or supplement of the applicable Indenture;

•

reduce the percentage of principal amount of debt securities necessary to waive compliance with some of the provisions of the applicable Indenture; or

•

modify provisions relating to amendment or waiver, except to increase percentages or to provide that other provisions of the applicable Indenture cannot be amended or waived without the consent of each holder affected.

We and each guarantor (if any) may amend or supplement either of the Indentures or waive any provision of such Indenture without the consent of any holders of debt securities in various circumstances, including:

•

to provide for the assumption of our obligations under the applicable Indenture and the debt securities by a successor;

•

to add covenants that would benefit the holders of any debt securities or to surrender any of our rights or powers;

•

to provide for the issuance of additional securities, including debt securities of a particular series, under the applicable Indenture;

•

to add events of default;

•

to provide any security for or guarantees of any series of debt securities;

•

to provide for the form or terms of any series of debt securities;

•

to appoint a successor trustee or to provide for the administration of the trusts under the applicable Indenture by more than one trustee;

•

to cure any ambiguity, omission, defect or inconsistency that does not adversely affect the interests of the holders of outstanding debt securities of any series;

•

to make any change to the extent necessary to permit or facilitate defeasance or discharge of any series of debt securities that does not adversely affect the interests of the holders of outstanding debt securities of any series;

•

to convey, transfer, assign, mortgage or pledge any property to or with the trustee;

•

to permit the qualification of the applicable Indenture under the Trust Indenture Act;

•

to change or eliminate any restriction on the payment of principal of, or premium, if any, on, any debt securities;

•

to add to, change or eliminate any of the provisions of the applicable Indenture in respect of one or more series of debt securities; provided, however, that any such addition, change or elimination not otherwise permitted shall neither apply to any debt security of any series created prior to the execution of such supplemental indenture and entitled to the benefit of such provision nor modify the rights of the holder of any such debt security with respect to such provision or shall become effective only when there is no such debt security outstanding;

•

reflect the release of any guarantor of its obligations under the guarantee, in the manner provided by the indenture; or

•

to make any change that does not affect the rights of any holder.

The holders of a majority in principal amount of the outstanding debt securities under either Indenture may waive our obligations to comply with various covenants, including those relating to:

•

our obligation to secure the debt securities in the event of mergers, consolidations and sales of assets;

•

corporate existence;

•

with respect to the senior debt securities, the restrictions on Liens and Sale/Leaseback Transactions; and

•

defeasance.

When we use the term defeasance, we mean discharge from some or all of our obligations under either Indenture. If we deposit with the trustee funds or government securities the maturing principal and interest of which is sufficient to make payments on the debt securities of a series on the dates those payments are due and payable, then, at our option, either of the following will occur:

•

“legal defeasance,” which means that we and each guarantor (if any) will be discharged from our obligations with respect to the debt securities of that series; or

•

“covenant defeasance,” which means that we will no longer have any obligation to comply with the restrictive covenants under the applicable Indenture and any other restrictive covenants that apply to that series of the debt securities, and the related events of default will no longer apply to us.

If we defease a series of debt securities, the holders of the debt securities of the series affected will not be entitled to the benefits of the applicable Indenture, to provide temporary debt securities, to register the transfer or exchange of debt securities, to replace stolen, lost or mutilated debt securities or to maintain paying agencies and hold money for payment in trust. In the case of covenant defeasance, our obligation to pay principal, premium and interest on the debt securities will also survive.

Unless we inform you otherwise in the prospectus supplement, we will be required to deliver to the trustee an opinion of counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for federal income tax purposes. If we elect legal defeasance, that opinion of counsel must be based upon a ruling from the Internal Revenue Service or a change in law to that effect.

Subordination Provisions for Subordinated Debt Securities

Any subordinated debt securities issued under the subordinated indenture will be subordinate and subject in right of payment to the prior payment in full of all of our Senior Indebtedness. The following provisions will apply to the subordinated debt securities unless otherwise specified in the prospectus supplement:

Subject to any collateral, security, assurance or guarantee provided for the benefit of any series of subordinated debt securities, if any, the payment of principal, any premium and interest on the subordinated debt securities will be subordinated in right of payment to the prior payment in full of all of our Senior Indebtedness. This means that in certain circumstances where we may not be making payments on all of our debt obligations as they become due, the holders of all of our Senior Indebtedness will be entitled to receive payment in full of all amounts that are due or will become due on the Senior Indebtedness before the holders of subordinated debt securities will be entitled to receive any payment or distribution (other than in the form of subordinated securities) on the subordinated debt securities. These circumstances include the following circumstances:

•

we make a payment or distribute assets to creditors upon any liquidation, dissolution, winding up or reorganization of our company, or as part of an assignment or marshalling of our assets for the benefit of our creditors;

•

we file for bankruptcy or certain other events in bankruptcy, insolvency or similar proceedings occur; and

•

the maturity of the subordinated debt securities is accelerated. For example, the entire principal amount of a series of subordinated debt securities may be declared to be due and immediately payable or may be automatically accelerated due to an event of default as described under “—Events of Default.”

In addition, we are generally not permitted to make payments of principal, any premium or interest on the subordinated debt securities if we default on our obligation to make payments on our Senior Indebtedness and do not cure such default. We are also prohibited from making payments on subordinated debt securities if an event of default (other than a payment default) that permits the holders of senior indebtedness to accelerate the maturity of the Senior Indebtedness occurs and we and the trustee have received a notice of such event of default. However, unless the senior indebtedness has been accelerated because of that event of default, this payment blockage upon notice cannot last more than 179 days.

These subordination provisions mean that if we are insolvent a holder of Senior Indebtedness is likely to ultimately receive out of our assets more than a holder of the same amount of our subordinated debt securities, and a creditor of ours that is owed a specific amount but who owns neither our Senior Indebtedness nor our subordinated debt securities may ultimately receive less than a holder of the same amount of Senior Indebtedness and more than a holder of subordinated debt securities.

The subordinated indenture does not limit the amount of senior indebtedness we are permitted to have and we may in the future incur additional senior indebtedness.

“Senior Indebtedness” is defined in the subordinated indenture to mean, with respect to us,

(i)

the principal, premium, if any, and interest (including interest, whether or not allowable, accruing after the filing of a petition initiating any proceeding under any state, federal or foreign bankruptcy law) in respect of (A) our indebtedness and obligations related thereto and (B) indebtedness evidenced by securities, debentures, notes, bonds or other similar instruments issued by us;

(ii)

all our capital lease, purchase money and similar obligations;

(iii)

all our obligations issued or assumed as the deferred purchase price of property, all our conditional sale obligations and all our obligations under any title retention agreement;

(iv)

all our obligations for the reimbursement of any letter of credit, any banker’s acceptance, any security purchase facility, any repurchase agreement or similar arrangement, any commercial paper, any interest rate swap, any other hedging arrangement, or any obligation under options or any similar credit or other transaction;

(v)

all obligations for indemnification, contributions, earnouts, adjustments of purchase price or similar obligations;

(vi)

all obligations in respect of workers compensation claims, self-insurance, indemnities, bid performance, warranty release, appeal, surety and similar bonds;

(vii)

all obligations of the type referred to in clauses (i) through (vi) above of other Persons for the payment of which we are responsible or liable as obligor, guarantor or otherwise;

(viii)

all obligations of the type referred to in clauses (i) through (vii) above of other Persons secured by any lien on any property or asset of ours (whether or not such obligation is assumed by us); and

(ix)

all renewals, extensions, modifications and refunding of obligations of the type referred to in clauses (i) through (viii) above; whether incurred on or prior to the date of the subordinated indenture or thereafter incurred. Notwithstanding the foregoing, “Senior Indebtedness” shall not include (1) any Additional Junior Indebtedness, (2) debt securities issued pursuant to the subordinated indenture and guarantees in respect of such debt securities, (3) our trade accounts payable arising in the ordinary course of business (such trade accounts payable being pari passu in right of payment to debt securities issued pursuant to the subordinated indenture), or (4) obligations with respect to which in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such obligations are pari passu or junior in right of payment to debt securities issued pursuant to the subordinated indenture. Senior Indebtedness shall continue to be Senior Indebtedness and be entitled to the subordination provisions irrespective of any amendment, modification or waiver of any term of such Senior Indebtedness.

“Additional Junior Indebtedness” is defined in the subordinated indenture to mean, without duplication and other than the subordinated debt securities, any indebtedness, liabilities, guarantees or obligations of ours or any of our subsidiaries, under debt securities (or guarantees in respect of debt securities or preferred securities) initially issued after the date of the subordinated indenture to any trust, or a trustee of a trust, partnership or other entity affiliated with us that is, directly or indirectly, a finance subsidiary (as such term is defined in Rule 3a-5 under the Investment Company Act of 1940) or other financing vehicle of ours or any subsidiary of ours in connection with the issuance by that entity of preferred securities or other securities that are issued on a pari passu basis with the subordinated debt securities.

If this prospectus is being delivered in connection with a series of subordinated securities, the accompanying prospectus supplement or the information incorporated by reference will set forth the approximate amount of senior indebtedness outstanding as of a recent date.

Guarantee

To the extent provided in a prospectus supplement and either a supplemental indenture or a resolution of our board of directors, in each case, relating to a particular series of debt securities, each of our subsidiaries that becomes a guarantor of the debt securities of such series, and any of our subsidiaries that is a successor thereto, will fully, irrevocably, unconditionally and absolutely guarantee the due and punctual payment of the principal of, and premium, if any, and interest on such debt securities, and all other amounts due and payable under the applicable indenture and such debt securities by us to the trustee or the holders of such debt securities, however, such guarantors will not otherwise be subject to the covenants, obligations and duties provided for in the indenture solely in their capacity as guarantors.

Satisfaction and Discharge

The Indentures will cease to be of further effect and will be deemed to have been satisfied and discharged with respect to a particular series of debt securities, when the following conditions have been satisfied:

•

all debt securities of that series have been delivered to the trustee for cancellation, or all debt securities of that series not previously delivered to the trustee for cancellation have become due and payable or will become due and payable at their stated maturity or on a redemption date within one year, and we:

•

irrevocably deposit with the trustee, in trust, funds sufficient to pay and discharge the entire indebtedness on the senior debt securities of that series that had not been previously delivered for cancellation, for principal (and premium, if any) and interest, if any, to the date of the deposit (for debt securities that have become due and payable) or to the stated maturity or the redemption date, as the case may be;

•

we have paid or caused to be paid all other sums payable under the applicable Indenture or have made arrangements for any such payments satisfactory to the payee; and

•

we have delivered to the trustee an officer’s certificate and opinion of counsel, each stating that all these conditions precedent provided for satisfaction and discharge of the Indenture have been complied with.

Governing Law

New York law governs the Indentures and the debt securities.

Trustee

U.S. Bank National Association is trustee under the Indentures. The Indentures contain limitations on the right of the trustee, if it becomes one of our creditors, to obtain payment of claims or to realize payment on property received for those claims, as security or otherwise. The trustee is permitted to engage in other transactions with us in the ordinary course of business. If, however, it acquires any conflicting interest, it must eliminate that conflict or resign.

Form, Exchange, Registration and Transfer

We will issue the debt securities in registered form, without interest coupons. We will not charge a service charge for any registration of transfer or exchange of the debt securities. We may, however, require the payment of any tax or other governmental charge payable for that registration.

Holders may exchange debt securities of any series for other debt securities of the same series, the same total principal amount and the same terms but in different authorized denominations in accordance with the applicable Indenture. Holders may present debt securities for registration of transfer at the office of the security registrar or any transfer agent we designate. The security registrar or transfer agent will effect the transfer or exchange when it is satisfied with the documents of title and identity of the person making the request.

We have appointed the trustee as security registrar for the debt securities. If a prospectus supplement refers to any transfer agent initially designated by us, we may at any time rescind that designation or approve a change in the location through which any transfer agent acts. We are required to maintain an office or agency for transfers and exchanges in each place of payment. We may at any time designate additional transfer agents for any series of debt securities.

In the case of any redemption, neither the security registrar nor the transfer agent will be required to register the transfer or exchange of any debt security either:

•

during a period beginning 15 business days prior to the mailing of the relevant notice of redemption and ending on the close of business on the day of mailing of that notice; or

•

if we have called the debt security for redemption in whole or in part, except the unredeemed portion of any debt security being redeemed in part.

Payment and Paying Agents

Unless we inform you otherwise in a prospectus supplement, payments on the debt securities will be made in U.S. dollars at the office of the trustee. At our option, however, we may make payments by check mailed to the holder’s registered address or, for global debt securities, by wire transfer. Unless we inform you otherwise in a prospectus supplement, we will make interest payments to the person in whose name the debt security is registered at the close of business on the record date for the interest payment.

Unless we inform you otherwise in a prospectus supplement, we have designated the trustee as our paying agent for payments on debt securities issued under the Indentures. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

Subject to the requirements of any applicable abandoned property laws, the trustee and paying agent will pay to us upon written request any money they are holding for payments on the debt securities that remain unclaimed for two years after the date upon which that payment has become due. After payment to us, holders entitled to the money must look to us for payment. In that case, all liability of the trustee or paying agent with respect to that money will cease.

Book-Entry Debt Securities

We may issue the debt securities of a series in the form of one or more global debt securities that would be deposited with a depositary or its nominee identified in the prospectus supplement. We may issue global debt securities in either temporary or permanent form. We will describe in the prospectus supplement the terms of any depositary arrangement and the rights and limitations of owners of beneficial interests in any global debt security.

DESCRIPTION OF GUARANTEE OF DEBT SECURITIES

To the extent provided in a prospectus supplement and either an indenture supplement or a resolution of our board of directors, in each case, relating to a particular series of debt securities, each of our subsidiaries that becomes a guarantor of the debt securities of such series, and any of our subsidiaries that is a successor thereto, will fully, irrevocably, unconditionally and absolutely guarantee the due and punctual payment of the principal of, and premium, if any, and interest on such debt securities, and all other amounts due and payable under the applicable indenture and such debt securities by us to the trustee or the holders of such debt securities, and any provisions permitting a release of such guarantee will be included in such prospectus supplement and indenture supplement or resolution, however, such guarantors will not otherwise be subject to the covenants, obligations and duties provided for in the indenture solely in their capacity as guarantors.

DESCRIPTION OF CAPITAL STOCK

General

We are authorized to issue a total of 1,300,000,000 shares of all classes of capital stock. Of those authorized shares, 1,200,000,000 are shares of common stock, 379,927,619 shares of which were outstanding as of July 3, 2017, and 100,000,000 are shares of preferred stock. Of the authorized preferred stock, there are 20,000,000 shares designated as Convertible Preferred Stock, Series A (none of which was outstanding on July 3, 2017), 30,000,000 shares designated as Convertible Preferred Stock, Series B (none of which was outstanding on July 3, 2017), 1,000,000 shares designated as Series C Participating Preferred Stock (none of which was outstanding on July 3, 2017), and 20,000 shares designated as Series E Non-Voting Perpetual Preferred Stock (all of which were outstanding on July 3, 2017).

The additional shares of our authorized stock available for issuance might be issued at times and under circumstances so as to have a dilutive effect on earnings per share and on the equity ownership of the holders of our common stock. The ability of our board of directors to issue additional shares of stock could enhance the board’s ability to negotiate on behalf of the shareholders in a takeover situation but could also be used by the board to make a change-in-control more difficult, thereby denying shareholders the potential to sell their shares at a premium and entrenching current management.

The following description is a summary of the material provisions of our capital stock and various provisions of our certificate of incorporation and bylaws. This summary is not intended to be complete and is qualified by reference to the provisions of applicable law and our certificate of incorporation and bylaws included as exhibits to the registration statement of which this prospectus is a part.

Common Stock

As of July 3, 2017, there were 13,514 holders of record. The issued and outstanding shares of common stock are validly issued, fully paid and non-assessable. Subject to any preferential rights of any prior ranking class or series of capital stock, including the preferred stock, holders of our common stock are entitled to receive dividends on that stock, payable either in cash, property or shares out of assets legally available for distribution when, as and if authorized and declared by our board of directors and to share ratably in our assets legally available for distribution to our shareholders in the event of liquidation, dissolution or winding-up. Subject to various exceptions, we will not be able to pay any dividend or make any distribution of assets on shares of our common stock until we pay dividends on any shares of preferred stock then outstanding with dividend or distribution rights senior to our common stock.

Holders of our common stock are entitled to one vote per share on all matters voted on by our shareholders, including the election of directors. Our certificate of incorporation does not provide for cumulative voting for the election of directors, which means that holders of more than one-half of the outstanding shares of our voting securities will be able to elect all of the directors then standing for election and holders of the remaining shares will not be able to elect any director.

Our board of directors may make rules and regulations concerning the transfer of shares of our common stock from time to time, in accordance with our bylaws.

Holders of our common stock will have no conversion, sinking fund or redemption rights.

Some provisions of the Oklahoma General Corporation Act, our certificate of incorporation and our bylaws may discriminate against holders of a substantial amount of the shares of our common stock. See “—Oklahoma Law” and “—Certificate of Incorporation and Bylaws.” Similarly, some provisions of our certificate of incorporation and our bylaws may have the effect of delaying, deferring or preventing a change-in-control with respect to an extraordinary corporate transaction, such as a merger, reorganization, tender offer, sale or transfer of substantially all of our assets.

Preferred Stock

Our board of directors is authorized to issue shares of preferred stock, in one or more series or classes, and to fix for each series or class the preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications, or terms or redemption, as are permitted by Oklahoma law and as are stated in the resolution or resolutions adopted by the board providing for the issuance of shares of that series or class.

Our board has authorized series designated as Convertible Preferred Stock, Series A and Convertible Preferred Stock, Series B. Our board has also authorized a series designated as Series C Participating Preferred Stock, which relates to our Second Amended and Restated Rights Agreement. No shares of Series C Participating Preferred Stock were issued, and the Second Amended and Restated Rights Agreement expired February 4, 2013, and was not renewed. Our board has further authorized a series of preferred stock designated as Series E Non-Voting Perpetual Preferred Stock, which is expected to pay quarterly dividends on each share, when, as and if declared by our board, at a rate of 5.5% per year. In April 2017, through a wholly owned subsidiary, we issued and contributed 20,000 shares of Series E Preferred Stock to ONEOK Foundation, Inc. for use in future charitable and nonprofit causes. No other shares of Series E Non-Voting Perpetual Preferred Stock have been issued.

When we offer to sell a particular series of preferred stock, we will describe the specific terms of the securities in a supplement to this prospectus. The prospectus supplement will also indicate whether the terms and provisions described in this prospectus apply to the particular series of preferred stock. The preferred stock will be issued under a certificate of designations relating to each series of preferred stock. The issuance of our preferred stock is also subject to our certificate of incorporation.

Preemptive Rights

No holder of any shares of any class of our stock has any preemptive or preferential right to acquire or subscribe for any unissued shares of any class of stock or any unauthorized securities, convertible into or carrying any right, option or warrant to subscribe for or acquire shares of any class of stock.

Oklahoma Law

Oklahoma Takeover Statute

We are subject to Section 1090.3 of the Oklahoma General Corporation Act. In general, Section 1090.3 prevents an “interested shareholder” from engaging in a “business combination” with an Oklahoma corporation for three years following the date that person became an interested shareholder, unless:

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prior to the date that person became an interested shareholder, our board of directors approved the business combination or the transaction in which the interested shareholder became an interested shareholder;

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upon consummation of the transaction that resulted in the interested shareholder becoming an interested shareholder, the interested shareholder owned at least 85% of our voting stock outstanding at the time the transaction commenced, excluding stock held by directors who are also officers of the corporation and stock held by certain employee stock plans; or

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on or subsequent to the date of the transaction in which that person became an interested shareholder, the business combination was approved by our board of directors and authorized at a meeting of shareholders by the affirmative vote of the holders of at least two-thirds of the outstanding voting stock of the corporation not owned by the interested shareholder.

Section 1090.3 defines a “business combination” to include:

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any merger or consolidation involving the corporation and an interested shareholder;

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any sale, transfer, pledge or other disposition of 10% or more of the assets of the corporation involving an interested shareholder;

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subject to limited exceptions, any transaction that results in the issuance or transfer by the corporation of the stock of the corporation to an interested shareholder;

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any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested shareholder; or

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the receipt by an interested shareholder of any loans, guarantees, pledges or other financial benefits provided by or through the corporation.

For purposes of the description above and Section 1090.3, the term “corporation” also includes our majority-owned subsidiaries. In addition, Section 1090.3, defines an “interested shareholder” as an entity or person beneficially owning 15% or more of our outstanding voting stock and any entity or person affiliated with or controlling or controlled by that entity or person.

Oklahoma Control Share Provisions

Our certificate of incorporation provides that we are not subject to the control share provisions of the Oklahoma General Corporation Act. With exceptions, these provisions prevent holders of more than 20% of the voting power of the stock of an Oklahoma corporation from voting their shares. If we were to become subject to the control share provisions of the Oklahoma General Corporation Act in the future, this provision may delay the time it takes anyone to gain control of us.

Certificate of Incorporation and Bylaws

Exculpation

Our certificate of incorporation provides that our directors and officers will not be personally liable for monetary damages for any action taken, or any failure to take any action, unless:

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the director or officer has breached his or her duty of loyalty to ONEOK or its shareholders;

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the breach or failure to perform constitutes an act or omission not in good faith or which involves intentional misconduct or a knowing violation of law;

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the director served at the time of payment of an unlawful dividend or an unlawful stock purchase or redemption, unless the director was absent at the time the action was taken or dissented from the action; or

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the director or officer derived an improper personal benefit from the transaction.

Indemnification

We will generally indemnify any person who was, is, or is threatened to be made, a party to a proceeding by reason of the fact that he or she:

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is or was our director, officer, employee or agent; or

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is or was serving at our request as a director, officer, employee or agent of another corporation, partnership, limited liability company, joint venture, trust or other enterprise or as a member of any committee or similar body.

Any indemnification of our directors, officers or others pursuant to the foregoing provisions for liabilities arising under the Securities Act are, in the opinion of the SEC, against public policy as expressed in the Securities Act and are unenforceable.

Shareholder Action; Special Meeting of Shareholders

Our certificate of incorporation eliminates the ability of our shareholders to act by written consent. Our bylaws provide that special meetings of our shareholders may be called only by a majority of the members of our board of directors.

Advance Notice Requirements for Shareholder Proposals

At any annual meeting of our shareholders, the only business that shall be brought before the meeting is that which is brought:

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pursuant to our notice of meeting;

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by or at the discretion of our board of directors; or

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by any of our shareholders of record at the time the notice is given, who are entitled to vote at the meeting and who comply with the notice procedures set forth in our bylaws as summarized below.

For business to be properly brought before an annual meeting by a shareholder pursuant to the immediately preceding clause, the shareholder must have given timely notice in writing to our secretary. To be timely as to an annual meeting of shareholders, a shareholder’s notice must be received at our principal executive offices not less than 120 calendar days before the date our proxy statement is released to shareholders in connection with the previous year’s annual meeting; provided however, that if the date of the meeting is changed by more than 30 days from the date of the previous year’s meeting, notice must be received no later than the close of business on the 10th day following the earlier of the day on which notice of the date of the meeting was mailed to shareholders or public disclosure of that date was made. The shareholder notice shall set forth as to each matter the shareholder proposes to bring before the meeting:

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a brief description of and the reasons for proposing the matter at the meeting;

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with respect to the shareholder giving notice and the beneficial owner, if any, on whose behalf the proposal is being made:

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the name and address of such person;

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the class or series and number of shares of ONEOK which are owned beneficially and of record by such person and any affiliates or associates of such person;

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the name of each nominee holder of shares of all stock of ONEOK owned beneficially but not of record by such person or any affiliates or associates of such person, and the number of such shares of stock of ONEOK held by each such nominee holder;

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whether and the extent to which any derivative instrument, swap, option, warrant, short interest, hedge or profit interest or other transaction has been entered into by or on behalf of such person, or any affiliates or associates of such person, with respect to stock of ONEOK; and

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whether and the extent to which any other transaction, agreement, arrangement or understanding (including any short position or any borrowing or lending of shares of stock of ONEOK) has been made by or on behalf of such person, or any affiliates or associates of such person, the effect or intent of any of the foregoing being to mitigate loss to, or to manage risk or benefit of stock price changes for, such person, or any affiliates or associates of such person, or to increase or decrease the voting power or pecuniary or economic interest of such person, or any affiliates or associates of such person, with respect to stock of ONEOK;

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a representation that the shareholder giving notice intends to appear in person or by proxy at the annual meeting to bring such business before the meeting;

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any material interest of the shareholder of record, the beneficial owner, if any, on whose behalf the proposal is made, or any affiliate or associate of any of the foregoing, in the proposal;

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a description of all agreements, arrangements and understandings between the shareholder, the beneficial owner, if any, on whose behalf the proposal is made or any affiliate or associate of any of the foregoing, and any other person or persons (including their names) in connection with the proposal of the business by the shareholder; and

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all other information that would be required to be disclosed by such person as a participant in a solicitation of proxies for the election of directors in a contested election, or would be otherwise required to be disclosed in connection with such solicitation, in each case pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended.

These provisions may impede shareholders’ ability to bring matters before an annual meeting of shareholders.

Higher Vote for Some Business Combinations and Other Actions

Subject to various exceptions, including acquiring 85% of the outstanding shares less shares owned by related persons in a single transaction, a business combination (including, but not limited to, a merger or consolidation, the sale, lease, exchange, mortgage, pledge, transfer or other disposition of our assets in excess of $5,000,000, various issuances and reclassifications of securities and the adoption of a plan or proposal for liquidation or dissolution) with or upon a proposal by a related person, who is a person that is the direct or indirect beneficial owner of more than 10% of the outstanding voting shares of our stock (subject to various exceptions), and any affiliates of that person, shall require, in addition to any approvals required by law, the approval of the business combination by either:

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a majority vote of all of the independent directors; or

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the holders of at least 66-2/3% of the outstanding shares otherwise entitled to vote as a single class with the common stock to approve the business combination, excluding any shares owned by the related person.

In addition, our certificate of incorporation provides that our bylaws may only be adopted, amended or repealed by a majority of the board of directors or by 80% of our shareholders, voting as a class. Our certificate of incorporation also requires the affirmative vote of 80% of our shareholders to amend, repeal or adopt provisions in our certificate of incorporation relating to, among other things,

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the number of directors and the manner of electing those directors, including the election of directors to newly created directorships;

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provisions relating to changes in the bylaws;

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a director’s personal liability to us or our shareholders;

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shareholder ratification of various contracts, transactions and acts; and

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voting requirements for approval of business combinations.

Transactions with Interested Parties

Our certificate of incorporation provides that, in the absence of fraud, no contract or other transaction will be affected or invalidated by the fact that any of our directors are in any way interested in or connected with any other party to the contract or transaction or are themselves parties to the contract or transaction, provided that the interest is fully disclosed or otherwise known to our board of directors at the meeting of the board at which the contract or transaction is authorized or confirmed, and provided further that a quorum of disinterested directors is present at the meeting of our board of directors authorizing or confirming the contract or transaction and the contract or transaction is approved by a majority of the quorum, and no interested director votes on the contract

or transaction. Any contract, transaction or act entered into or taken by us or our board or any committee thereof that is ratified by a majority of a quorum of the shareholders having voting power at any annual meeting, or any special meeting called for that purpose, will be valid and binding as though ratified by all of our shareholders. Any director may vote upon any contract or other transaction between us and any subsidiary corporation without regard to the fact that he is also a director of that subsidiary corporation. No contract or agreement between us and any other corporation or party that owns a majority of our capital stock or any subsidiary of that other corporation shall be made or entered into without the affirmative vote of a majority of the whole board of directors at a regular meeting of the board.

Transfer Agent and Registrar

The current transfer agent and registrar for our common stock is Wells Fargo Shareholder Services, a division of Wells Fargo Bank, N.A.

DESCRIPTION OF STOCK PURCHASE CONTRACTS

AND STOCK PURCHASE CONTRACT UNITS

We may issue stock purchase contracts for the purchase of our securities or securities of an entity unaffiliated or affiliated with us, a basket of such securities or any combination of the above as specified in the applicable prospectus supplement. Each stock purchase contract will entitle the holder thereof to purchase, and obligate us to sell, on specified dates, such securities, at a specified purchase price, all as set forth in the applicable prospectus supplement. The applicable prospectus supplement will also specify the methods by which the holders may purchase such securities, any acceleration, cancellation or termination provisions or other provisions relating to the settlement of a stock purchase contract and, if applicable, the identity of any of our subsidiaries guaranteeing our obligations with respect to such stock purchase contracts. Stock purchase contracts may require holders to satisfy their obligations thereunder when the stock purchase contracts are issued. Our obligation to settle such prepaid stock purchase contracts on the relevant settlement date may constitute indebtedness. Accordingly, the prepaid stock purchase contracts will be issued under one of the Indentures. The stock purchase contracts may be issued separately or as part of a stock purchase contract unit that consists of (a) a stock purchase contract and (b) senior or subordinated debt securities, or preferred stock, U.S. Treasury securities or other debt obligations of third parties, that may be used to secure the holders’ obligations under a stock purchase contract. The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase contract units, and such payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations in a specified manner and, in certain circumstances, we may deliver newly issued prepaid stock purchase contracts upon release to a holder of any collateral securing such holder’s obligations under the original stock purchase contract.

The applicable prospectus supplement will describe the general terms of any stock purchase contracts or stock purchase contract units and, if applicable, prepaid stock purchase contracts. The description in the prospectus supplement will not purport to be complete and will be qualified in its entirety by reference to (a) the stock purchase contracts, (b) the collateral arrangements and depository arrangements, if applicable, relating to such stock purchase contracts or stock purchase contract units and (c) if applicable, the prepaid stock purchase contracts and the documents pursuant to which such prepaid stock purchase contracts will be issued. Some of the material United States federal income tax considerations applicable to the stock purchase contracts and the stock purchase contract units will also be discussed in the applicable prospectus supplement.

DESCRIPTION OF DEPOSITARY SHARES

General

We may, at our option, elect to offer fractional shares of preferred stock, rather than full shares of preferred stock. If we exercise this option, we will issue to the public receipts for depositary shares, and each of these depositary shares will represent a fraction (to be set forth in the applicable prospectus supplement) of a share of a particular series of preferred stock.

The shares of any series of preferred stock underlying the depositary shares will be deposited under a deposit agreement between us and a bank or trust company selected by us. The depositary will have its principal office in the United States and a combined capital of at least $50,000,000. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, in proportion, to the applicable fraction of a share of preferred stock underlying that depositary share, to all the rights and preferences of the preferred stock underlying that depositary share. Those rights (to be set forth in the applicable prospectus supplement) include dividend, voting, redemption and liquidation rights.

The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement. Depositary receipts will be distributed to those persons purchasing the fractional shares of preferred stock underlying the depositary shares, in accordance with the terms of the offering. Copies of the forms of deposit agreement and depositary receipt will be filed as exhibits to the registration statement. The following summary of the deposit agreement, the depositary shares and the depositary receipts is not complete. You should refer to the forms of the deposit agreement and depositary receipts that will be filed with the SEC in connection with the offering of the specific depositary shares.

Pending the preparation of definitive engraved depositary receipts, the depositary may, upon our written order, issue temporary depositary receipts substantially identical to the definitive depositary receipts but not in definitive form. These temporary depositary receipts entitle their holders to all the rights of definitive depositary receipts which are to be prepared without unreasonable delay. Temporary depositary receipts will then be exchangeable for definitive depositary receipts at our expense.

Dividends and Other Distributions

The depositary will distribute all cash dividends or other cash distributions received with respect to the preferred stock to the record holders of depositary shares relating to the preferred stock in proportion to the number of depositary shares owned by those holders.

If there is a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares that are entitled to receive the distribution, unless the depositary determines that it is not feasible to make the distribution. If this occurs, the depositary may, with our approval, sell the property and distribute the net proceeds from the sale to the applicable holders.

Redemption of Depositary Shares

If a series of preferred stock represented by depositary shares is subject to redemption, the depositary shares will be redeemed from the proceeds received by the depositary resulting from the redemption, in whole or in part, of that series of preferred stock held by the depositary. The redemption price per depositary share will be equal to the applicable redemption fraction of the redemption price per share payable with respect to that series of the preferred stock. Whenever we redeem shares of preferred stock that are held by the depositary, the depositary will redeem, as of the same redemption date, the number of depositary shares representing the shares of preferred stock so redeemed. If fewer than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or pro rata as may be determined by the depositary.

Voting the Preferred Stock

Upon receipt of notice of any meeting at which the holders of the preferred stock are entitled to vote, the depositary will mail the information contained in such notice to the record holders of the depositary shares underlying the preferred stock. Each record holder of the depositary shares on the record date, which will be the same date as the record date for the preferred stock, will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the amount of the preferred stock represented by the holder’s depositary shares. The depositary will then try, as far as practicable, to vote the number of shares of preferred stock underlying those depositary shares in accordance with such instructions. We will agree to take all actions which may be deemed necessary by the depositary to enable the depositary to do so. The depositary will not vote the shares of preferred stock to the extent it does not receive specific instructions from the holders of depositary shares underlying the preferred stock.

Amendment and Termination of the Depositary Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the depositary. However, any amendment which materially and adversely alters the rights of the holders of depositary shares will not be effective unless the amendment has been approved by the holders of at least a majority of the depositary shares then outstanding. The deposit agreement may be terminated by us or by the depositary only if (a) all outstanding depositary shares have been redeemed or (b) there has been a final distribution of the underlying preferred stock in connection with our liquidation, dissolution or winding up and the preferred stock has been distributed to the holders of depositary receipts.

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will also pay charges of the depositary in connection with the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary receipts will pay other transfer and other taxes and governmental charges and those other charges, including a fee for the withdrawal of shares of preferred stock upon surrender of depositary receipts, as are expressly provided in the deposit agreement to be for their accounts.

Miscellaneous

The depositary will forward to holders of depositary receipts all reports and communications from us that we deliver to the depositary and that we are required to furnish to the holders of the preferred stock.

Neither we nor the depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond our control in performing our respective obligations under the deposit agreement. Our obligations and those of the depositary will be limited to performance in good faith of our respective duties under the deposit agreement. Neither we nor the depositary will be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. We and the depositary may rely upon written advice of counsel or accountants, or upon information provided by persons presenting preferred stock for deposit, holders of depositary receipts or other persons believed to be competent and on documents believed to be genuine.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering notice to us of its election to resign. We may remove the depositary at any time. Any resignation or removal will take effect upon the appointment of a successor depositary and its acceptance of the appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of debt securities, preferred stock, common stock, or units of two or more of these types of securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any registered holders of warrants or beneficial owners of warrants.

We will distribute a prospectus supplement with regard to each issue of warrants. Each prospectus supplement will describe:

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in the case of warrants to purchase debt securities, the designation, aggregate principal amount, currencies, denominations and terms of the series of debt securities purchasable upon exercise of the warrants and the price at which you may purchase the debt securities upon exercise;

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in the case of warrants to purchase preferred stock, the designation, number of shares, stated value and terms, such as liquidation, dividend, conversion and voting rights, of the series of preferred stock purchasable upon exercise of the warrants and the price at which you may purchase such number of shares of preferred stock of such series upon such exercise;

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in the case of warrants to purchase common stock, the number of shares of common stock purchasable upon the exercise of the warrants and the price at which you may purchase such number of shares of common stock upon such exercise;

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the period during which you may exercise the warrants;

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any provision adjusting the securities that may be purchased on exercise of the warrants, and the exercise price of the warrants, to prevent dilution or otherwise;

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the place or places where warrants can be presented for exercise or for registration of transfer or exchange; and

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any other material terms of the warrants.

Warrants for the purchase of preferred stock and common stock will be offered and exercisable for U.S. dollars only. Warrants will be issued in registered form only. The exercise price for warrants will be subject to adjustment as described in the applicable prospectus supplement.

Prior to the exercise of any warrants to purchase debt securities, preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the debt securities, preferred stock or common stock purchasable upon exercise, including:

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in the case of warrants for the purchase of debt securities, the right to receive payments of principal of, any premium or interest on the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

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in the case of warrants for the purchase of preferred stock or common stock, the right to vote or to receive any payments of dividends on the preferred stock or common stock purchasable upon exercise.

PLAN OF DISTRIBUTION

We may sell our securities through agents, underwriters or dealers, or directly to purchasers.

We may designate agents to solicit offers to purchase our securities.

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We will name any agent involved in offering or selling our securities, and any commissions that we will pay to the agent, in our prospectus supplement.

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Unless we indicate otherwise in our prospectus supplement, our agents will act on a best-efforts basis for the period of their appointment.

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Our agents may be deemed to be underwriters under the Securities Act of any of our securities that they offer or sell.

We may use one or more underwriters in the offer or sale of our securities.

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If we use an underwriter, we will execute an underwriting agreement with the underwriter(s) at the time that we reach an agreement for the sale of our securities.

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We will include the names of the managing underwriter(s), as well as any other underwriters, and the terms of the transaction, including the compensation the underwriters and dealers will receive, in our prospectus supplement.

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The underwriter(s) will use our prospectus supplement to sell our securities.

We may use a dealer to sell our securities.

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If we use a dealer, we, as principal, will sell our securities to the dealer.

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The dealer will then sell our securities to the public at varying prices that the dealer will determine at the time it sells our securities.

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We will include the name of the dealer and the terms of our transactions with the dealer in our prospectus supplement.

We may directly solicit offers to purchase our securities, and we may directly sell our securities to institutional or other investors. We will describe the terms of our direct sales in our prospectus supplement.

We may indemnify agents, underwriters and dealers against certain liabilities, including liabilities under the Securities Act.

We may authorize our agents and underwriters to solicit offers by certain institutions to purchase our securities at the public offering price under delayed delivery contracts.

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If we use delayed delivery contracts, we will disclose that we are using them in the prospectus supplement and will tell you when we will demand payment and delivery of the securities under the delayed delivery contracts.

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These delayed delivery contracts will be subject only to the conditions that we set forth in the prospectus supplement.

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We will indicate in our prospectus supplement the commission that underwriters and agents soliciting purchases of our securities under delayed delivery contracts will be entitled to receive.

Underwriters, dealers and agents and their affiliates may engage in transactions with, or perform services for, or be customers of ONEOK and its affiliates in the ordinary course of business.

Other than our common stock, all securities offered by this prospectus will be a new issue of securities with no established trading market. Any underwriter to whom securities are sold by us for public offering and sale may make a market in such securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The securities may or may not be listed on a national securities exchange or a foreign securities exchange, except for the common stock which is currently listed and traded on the New York Stock Exchange. Any common stock sold by this prospectus will be listed for trading on the New York Stock Exchange subject to official notice of issuance. We cannot give you any assurance as to the liquidity of the trading markets for any securities.

LEGAL MATTERS

The validity of the securities being offered hereby will be passed upon for us by GableGotwals, Tulsa, Oklahoma, except that Fried, Frank, Harris, Shriver & Jacobson LLP, New York, New York, will pass upon such matters to the extent governed by New York law.

EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) incorporated in this Prospectus by reference to ONEOK, Inc.’s Current Report on Form 8-K dated July 6, 2017 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

LOGO

19,000,000 Shares of

Common Stock

PROSPECTUS SUPPLEMENT

Credit Suisse

January , 2018