UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities
Exchange Act of 1934 (Amendment No.  )

Filed by the Registrant þ
Filed by a Party other than the Registrant o

Check the appropriate box:

o		Preliminary Proxy Statement
o		Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
o		Definitive Proxy Statement
þ		Definitive Additional Materials
o		Soliciting Material Pursuant to §240.14a-12

 

Willbros Group, Inc.

(Name of Registrant as Specified In Its Charter)

 

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

þ		No fee required.
o		Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.

	(1)		Title of each class of securities to which transaction applies:
	(2)		Aggregate number of securities to which transaction applies:
	(3)		Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (set forth the amount on which the filing fee is calculated and state how it was determined):
	(4)		Proposed maximum aggregate value of transaction:
	(5)		Total fee paid:

o		Fee paid previously with preliminary materials.
o		Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

	(1)		Amount Previously Paid:
	(2)		Form, Schedule or Registration Statement No.:
	(3)		Filing Party:
	(4)		Date Filed:

WILLBROS GROUP, INC.
Plaza 2000 Building
50th Street, 8th Floor
P. O. Box 0816-01098
Panama, Republic of Panama

     As disclosed in a proxy statement dated April 23, 2008, the 2008 Annual Meeting of Stockholders (the “Annual Meeting”) of Willbros Group, Inc. (the “Company”) is to be held on Thursday, May 29, 2008, at 9:00 a.m. (local time), at the Panama Marriott Hotel, Calle 52 y Ricardo Arias — Area Bancaria, Panama City, Panama. Proposal 2 included in the proxy statement distributed by the Company in connection with the Annual Meeting relates to a proposed amendment to the Willbros Group, Inc. 1996 Stock Plan (the “1996 Stock Plan”). As described in the proxy statement, the sole purpose of the amendment to the 1996 Stock Plan is to increase the number of shares of Common Stock of the Company authorized for issuance under the 1996 Stock Plan by 750,000. Proposal 3 included in the proxy statement relates to a proposed amendment to the Willbros Group, Inc. Amended and Restated 2006 Director Restricted Stock Plan (the “2006 Director Plan”). As described in the proxy statement, the sole purpose of the amendment to the 2006 Director Plan is to increase the number of shares of common stock of the Company authorized for issuance under the 2006 Director Plan by 200,000.

     In connection with the proposed amendments to the 1996 Stock Plan and the 2006 Director Plan, the Company undertakes that beginning with 2008 and for the years ended December 31, 2008, 2009 and 2010, the Company’s prospective three-year average burn rate with respect to its equity awards will not exceed the greater of two percent of its common shares outstanding or the mean and one standard deviation of its Global Industry Classification Standards Peer Group (1010 — Energy) of 3.09 percent. This undertaking will apply to shares issued pursuant to the 1996 Stock Plan and the 2006 Director Plan. For the purposes of calculating the three-year average burn rate, each restricted stock (unit) or stock award or any forms of full-value awards granted under the Company’s equity plans will be counted as 2.0 award shares. The burn rate will be calculated as (i) the number of equity awards granted in each fiscal year by the Company to employees and directors, excluding awards granted to replace securities assumed in connection with a business combination transaction, divided by (ii) the weighted average basic common shares outstanding for the fiscal year.

May 22, 2008