Filed by Pfizer Inc.
                          pursuant to Rule 425 under the Securities Act of 1933
                                          and deemed filed pursuant Rule 14a-12
                                         of the Securities Exchange Act of 1934
                                                  Commission File No: 001-02516
                                              Subject Company:  Pharmacia Corp.

THE FOLLOWING PRESS RELEASE WAS DISSEMINATED BY PFIZER INC. AND PHARMACIA
CORPORATION ON JULY 15, 2002

For Immediate Release                    Contact: Andy McCormick
July 15, 2002                                     Pfizer Inc.
                                                  212-573-1226

                                                  Paul Fitzhenry
                                                  Pharmacia Corp.
                                                  908-901-8770

        PFIZER TO ACQUIRE PHARMACIA CORPORATION FOR $60 BILLION IN STOCK,
                STRATEGICALLY POSITIONING COMPANY FOR LONG-TERM
             LEADERSHIP IN RAPIDLY CHANGING PHARMACEUTICAL INDUSTRY
                                       ---
   FAST-GROWING COMPANIES HAVE PARTNERED SINCE 1998 TO MAKE ARTHRITIS MEDICINE
  CELEBREX THE MOST SUCCESSFUL NEW PHARMACEUTICAL LAUNCH EVER; COMBINED COMPANY
 EXPECTED TO HAVE AS MANY AS 12 PRODUCTS WITH ANNUAL REVENUES GREATER
                                 THAN $1 BILLION
                                       ---
       COMBINED R&D PIPELINE WILL HAVE NEARLY 120 NEW CHEMICAL ENTITIES IN
         DEVELOPMENT AND OVER 80 IN-LINE PRODUCT ENHANCEMENT PROGRAMS;
       PFIZER THERAPEUTIC PORTFOLIO TO BE ENHANCED BY PHARMACIA'S STRENGTH
                  IN ONCOLOGY, OPHTHALMOLOGY AND ENDOCRINOLOGY
                                       ---

      TRANSACTION EXPECTED TO BE NON-DILUTIVE TO ADJUSTED DILUTED EARNINGS
                  PER SHARE IN 2003 AND ACCRETIVE THEREAFTER;
           PEAK YEAR SYNERGIES OF $2.5 BILLION TO BE ACHIEVED BY 2005

                                       ---

        PFIZER TO EXPAND EXISTING SHARE PURCHASE PROGRAM TO $16 BILLION;
                 PHARMACIA TRANSACTION IS MAJOR REDEPLOYMENT OF
                PFIZER ASSETS INTO CORE PHARMACEUTICALS BUSINESS

NEW YORK, N.Y. AND PEAPACK, N.J., JULY 15 - Pfizer Inc. (NYSE:PFE) and Pharmacia
Corporation (NYSE: PHA) jointly announced today that they have signed a
definitive agreement providing for Pfizer to acquire Pharmacia in a
stock-for-stock transaction valued at $60 billion,

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expanding the company's core strengths in pharmaceuticals and health care.

Pharmacia also announced that its Board of Directors intends to proceed with its
previously announced spin-off of its remaining 84% ownership of Monsanto (NYSE:
MON) to its current shareholders. After the Monsanto spin-off, Pfizer will
exchange 1.4 shares of Pfizer common stock for each outstanding share of
Pharmacia stock in a tax-free transaction valued at $45.08 per Pharmacia share,
based on Pfizer's July 12 closing stock price of $32.20. This transaction
represents a 44% premium based on the average closing prices of the two stocks
over the last 30 days, adjusted for the Monsanto spin-off.

"This is an extraordinary opportunity to combine two of the fastest-growing and
most innovative pharmaceutical companies and to position Pfizer for sustained
long-term leadership of the global pharmaceutical industry," said Hank
McKinnell, chairman and chief executive officer of Pfizer. "By combining with
Pharmacia, we are ensuring that our core capabilities in the discovery,
development and commercialization of new medicines are strong around the world.

"Our industry is changing rapidly. Remarkable advances in the scientific
understanding of the origins of disease will sharply increase drug discovery
targets and will create major opportunities for Pfizer. But it is increasingly
costly to fund the high-risk and long-term research required to develop
pharmaceutical products. At the same time, payers and providers want high value
and affordable medicines.

"We intend to meet these challenges head on. Our new company will be positioned
to deliver a stream of innovative new products and cost-effective health care
solutions. With Pharmacia, we will have the products, pipeline, scale, and
financial flexibility to extend our leadership."


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"Combining Pfizer with Pharmacia is a strategic opportunity that immediately
creates a global pharmaceutical company with unsurpassed resources and
capabilities," said Fred Hassan, chairman and chief executive officer of
Pharmacia Corporation.

"Our companies are already highly effective partners as shown by the
extraordinary success of the COX-2 products. A strategic combination with the
industry leader, Pfizer, will now give us the opportunity to maximize the
potential of both our current products and our pipeline.

"We are proud of our Pharmacia people, whose world-class capabilities have
enabled us to deliver outstanding performance and value. We are also pleased
that our shareholders will receive not only an immediate premium for their
shares, but also the opportunity to participate in Pfizer's long-term growth
with its truly outstanding product line and exciting pipeline."

Upon closing of the transaction, Mr. Hassan will become Vice Chairman of Pfizer,
assisting with integration and corporate strategy, and a member of the Pfizer
Board of Directors.

Dr. McKinnell cited other key attributes of the combined company:

     o A product portfolio unequalled in depth and breadth.
       -   The companies' combined product portfolios are highly complementary.
       -   By combining with Pharmacia, Pfizer will have the opportunity to
           support as many as 12 products with annual revenues greater than
           $1 billion.
       -   Category leadership includes key products in cardiovascular,
           endocrinology, neuroscience, arthritis and inflammation,
           infectious diseases, urology, ophthalmology and oncology.
       -   The combined portfolio will have a strong patent position.

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     o A stronger pipeline and expanded R&D program.
       -   The combined company will have an R&D pipeline containing nearly
           120 new chemical entities in development and over 80 additional
           projects for product enhancements.
       -   The companies' combined R&D budget for 2002 exceeds $7 billion,
           making it by far the largest privately funded biomedical
           research organization in the world.
       -   With Pharmacia, Pfizer plans to file 20 new drug applications
           with global regulatory authorities over the next five years.
       -   Pfizer's late-stage pipeline will be enhanced by major Pharmacia
           products that include eplerenone, a new category of treatment
           for cardiovascular diseases; parecoxib, the first injectable
           selective COX-2 inhibitor; and CDP-870 for rheumatoid arthritis.

     o Enhanced scale and financial flexibility.
       -   Pfizer and Pharmacia will have combined annual revenues for 2002 of
           approximately $48 billion, including $39 billion in prescription
           sales.
       -   Already the leading pharmaceutical company in the United States
           and Canada, Pfizer with Pharmacia will move from fourth to first
           in Europe; from third to first in Japan; and from fifth to first
           in Latin America in pharmaceutical sales.
       -   Synergies will be phased in, starting at $1.4 billion in 2003 and
           increasing to $2.2 billion in 2004 and $2.5 billion in 2005.

"By combining Pfizer with Pharmacia, we will have the financial and human
resources to bring new product opportunities to the market and to fund them to
their full potential. We met or exceeded all of our targets in the integration
of Warner-Lambert, and we anticipate


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another successful integration given that our two organizations have worked so
successfully on Celebrex and Bextra," Dr. McKinnell said.

                             KEY PRODUCT HIGHLIGHTS

Karen Katen, executive vice president of Pfizer and president of Pfizer's global
pharmaceutical business, said: "The combination of Pharmacia's portfolio with
Pfizer's brand-name franchises represents a superb opportunity to strengthen our
relationships with prescribing physicians and continue patient education and
outreach focused on helping people live longer and healthier lives. With
Pharmacia, we are ensuring that millions of patients around the world will
continue to benefit from our skill in developing therapies for cancer,
cardiovascular disease, mental health, respiratory and infectious diseases, eye
disease, and many other areas of medical need. Our medical mission has never
been more important, and as we look ahead with excitement and anticipation, I am
especially proud of Pfizer people and their dedication to the needs of
patients."

Ms. Katen reviewed the key new products that will be added to Pfizer's portfolio
of major products:

     o   In 1999, Pfizer and Pharmacia jointly introduced the anti-inflammatory
         Celebrex, the first-in-class selective COX-2 inhibitor. It was the most
         successful new product launch ever in the industry. This medicine has
         become the number one branded treatment for arthritis in the world, and
         it has been prescribed to more than 35 million patients worldwide. With
         its recent approval in the U.S. for acute pain and for dysmenorrhea,
         Celebrex has the most complete range of approved indications among
         selective COX-2 inhibitors on the market today.
     o   Pfizer and Pharmacia sales representatives began promoting a second
         selective COX-2 inhibitor, Bextra, in April, 2002. Together, Celebrex
         and Bextra now account for over 23% of new


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          NSAID prescriptions. In addition, launches of Bextra and parecoxib
          (branded Dynastat in Europe) are in progress in a number of
          international markets. Pharmacia is currently conducting studies to
          support the NDA filing for parecoxib in the U.S.
     o   Pharmacia's Xalatan (latanoprost ophthalmic solution) lowers eye
         pressure in patients with open-angle glaucoma not controlled by other
         medications. This revolutionary treatment for glaucoma is now the
         leading ophthalmic prescription medicine in the world.
     o   Pharmacia's Genotropin, the world's top-selling recombinant growth
         hormone, is indicated for the treatment of children and adults with
         growth hormone deficiency.
     o   Pharmacia also has world-class oncology products, which include
         Camptosar for treatment of metastatic colorectal cancer as well as
         therapies for breast cancer.

Most major Pfizer products are patent protected through this decade. For
example, U.S. patents for Lipitor expire in 2010, and for Viagra in 2011.
Pharmacia's most significant U.S. patents expire in the next decade (Celebrex in
2013, Bextra in 2015).

                                 R&D HIGHLIGHTS

Peter B. Corr, Ph.D., senior vice president science and technology for Pfizer,
said: "We will sharpen the focus of our R&D efforts to concentrate on compounds
that can be differentiated as truly innovative in an increasingly competitive
marketplace, deliver our joint late-stage programs to registration and build our
discovery and exploratory human development programs for the future. The
practical impact of combining with Pharmacia is very simple: we will have many
more candidates, more financial flexibility and human resources to support them,
and the best chance to find the maximum number of innovative medicines. We will
also expand our presence into new therapeutic categories, including the addition
of strong oncology and ophthalmology products to Pfizer's existing R&D programs
in these

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areas. With our expanded global scientific and medical resources, I am very
confident that we will deliver more and more medical breakthroughs to patients
who look to us for new treatments and cures for a host of serious diseases."

Pharmacia's pipeline includes treatments for cardiovascular disease, CNS
disorders, ophthalmic conditions, infectious diseases, urology, endocrinology,
oncology and arthritis/inflammation. Pharmacia has four compounds undergoing
regulatory review and five Phase III candidates.

                              FINANCIAL INFORMATION

David Shedlarz, executive vice president and chief financial officer of Pfizer,
said: "This acquisition underscores our commitment to redeploying our
substantial financial resources to fund growth opportunities in our core
pharmaceuticals business. Our combination with Pharmacia will greatly strengthen
our global pharmaceuticals business and through it we will gain valuable
efficiencies and productivity improvements."

Mr. Shedlarz cited the following other factors:

     o   Pfizer's shareholders will own approximately 77% of the combined
         company, and Pharmacia's shareholders will own approximately 23%. The
         transaction is expected to close by year-end 2002, subject to the
         approval by shareholders of both companies, necessary governmental and
         regulatory approvals and other usual and customary closing conditions.
     o   Excluding the effects of purchase accounting and merger-related
         expenses, the transaction is expected to be non-dilutive to Pfizer's
         2003 adjusted diluted earnings per share and $0.06 accretive in 2004.
         (Adjusted earnings is defined in Appendix A.)
     o   In a second-quarter earnings report released this morning, Pfizer
         reaffirmed its guidance of double-digit revenue growth in 2002. The
         company refined its guidance for 2002 diluted EPS, excluding


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         the cumulative effect of an accounting change, certain significant
         items and merger-related costs, to $1.58, or 21% growth, which is
         within the range of earlier guidance. Pharmacia released a statement
         this morning that expresses comfort with consensus estimates for the
         second quarter 2002, and reaffirms guidance of $1.52-1.57 EPS for the
         full year 2002.
     o   From 2002 to 2004 on a stand-alone basis, Pfizer expects compounded
         annual revenue growth of 11%, growth in net income of 14%, and growth
         in diluted EPS of 16%, excluding the cumulative effect of the change in
         accounting principle, certain significant items and merger-related
         costs.
     o   On a pro forma basis, the combined entity will have $11.9 billion in
         adjusted earnings and $47.9 billion in revenues in 2002. It is forecast
         to have a compounded annual growth from 2002 to 2004 of 10% for
         revenues and 19% for adjusted earnings. Pro forma revenue of the entity
         is forecast to increase to $57.8 billion, and adjusted earnings to
         $16.7 billion ($2.18 per share), by 2004. Adjusted diluted earnings per
         share of $2.18 in 2004 are $0.06 higher than Pfizer's stand-alone
         estimate of $2.12. (See Appendix B.)
     o   Indicative of the exceptional financial strength of the company, Pfizer
         said that it would expand its previously announced share repurchase
         program from $10 billion to $16 billion via open market purchases, as
         circumstances and prices warrant, as well as accelerate the buyback
         period with the anticipation of completing it in 2003.

Dr. McKinnell concluded, "This is a major step toward fulfilling our mission of
becoming the most valued company to patients, customers, colleagues, investors,
business partners, and the communities where we work and live. As a major global
pharmaceutical company, we understand the responsibilities of leadership, and we
will continue to address affordability and access issues. Our continuing
outreach will include


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innovative policy solutions, as well as expanding public/private partnerships
that address global public health issues.

"By joining with Pharmacia, we will remain at the forefront of medical
innovation, working on behalf of patients to ensure they receive the benefits of
breakthrough medicines."

Pfizer invites investors and the general public to listen, at www.pfizer.com, to
a webcast of a conference call with investment analysts at 11:00 a.m. EDT today,
15 July.

Pfizer was advised by Lazard and Bear Stearns & Co. Inc. Pharmacia was advised
by Goldman Sachs and Company.

Cadwalader, Wickersham and Taft provided legal counsel to Pfizer and Sullivan &
Cromwell provided legal counsel to Pharmacia.



DISCLOSURE NOTICE: THE INFORMATION CONTAINED IN THIS DOCUMENT IS AS OF JULY 15,
2002. THE COMPANY ASSUMES NO OBLIGATION TO UPDATE ANY FORWARD-LOOKING STATEMENTS
CONTAINED IN THIS DOCUMENT AS A RESULT OF NEW INFORMATION OR FUTURE EVENTS OR
DEVELOPMENTS.

This document and the attachments contain forward-looking information about the
Company's financial results and estimates, business prospects, and products in
research that involve substantial risks and uncertainties. You can identify
these statements by the fact that they use words such as "anticipate,"
"estimate," "expect," "project," "intend," "plan," "believe," and other words
and terms of similar meaning in connection with any discussion of future
operating or financial performance. Among the factors that could cause actual
results to differ materially are the following: the success of research and
development activities and the speed with which regulatory authorizations and
product launches may be achieved; competitive developments affecting our current
growth products; the ability to successfully market both new and existing
products domestically and internationally; difficulties or delays in
manufacturing; trade buying patterns; ability to meet generic and branded
competition after the expiration of the Company's patents; trends toward managed
care and health-care cost containment; possible U.S. legislation affecting
pharmaceutical pricing and reimbursement or Medicare; exposure to product
liability and other types of lawsuits; contingencies related to actual or
alleged environmental



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contamination; the Company's ability to protect its intellectual property both
domestically and internationally; interest rate and foreign currency exchange
rate fluctuations; governmental laws and regulations affecting domestic and
foreign operations, including tax obligations; changes in generally accepted
accounting principles; any changes in business, political, and economic
conditions due to the threat of future terrorist activity in the U.S. and other
parts of the world, and related U.S. military action overseas; growth in costs
and expenses; changes in our product mix; and the impact of acquisitions,
divestitures, restructurings, product withdrawals, and other unusual items,
including our ability to obtain the anticipated results and synergies from our
announced proposed acquisition of Pharmacia and the increased uncertainty
created by the integration of the two businesses, as well as the timing and
success of the announced exploration of strategic options of the Adams,
Schick-Wilkinson Sword, and Tetra businesses. A further list and description of
these risks, uncertainties, and other matters can be found in the Company's
Annual Report on Form 10-K for the fiscal year ended December 31, 2001, and in
its periodic reports on Forms 10-Q and 8-K (if any).


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APPENDIX A. ACCOUNTING INFORMATION - ADJUSTED EARNINGS


         A.       GAAP NET INCOME


         + Cumulative effect of change in accounting principle(1)

         + Certain significant items(1)

         + Effect of purchase price allocations on assets

                  o      Write-off of in-process R&D
                  o      Amortization of identifiable intangibles
                  o      Effect of write-up of assets to fair market value

         + Merger-related costs

                  o      Integration expenses
                  o      Restructuring charges


         = ADJUSTED EARNINGS





(1) See Pfizer Second Quarter Earnings Release.




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APPENDIX B. FINANCIAL INFORMATION




                                                                                              2002-2004
                                            2002              2003              2004             CAGR
                                            ----              ----              ----          ---------
                                                                                     
PFIZER
Total Revenues                              $35.1             $39.0            $42.9             11%
Net Income(1)                               $ 9.8             $11.3            $12.7             14%
Diluted EPS(1)                              $1.58             $1.84            $2.12             16%


COMBINED ENTITY
Total Revenues                              $47.9(2)+         $52.8(2)         $57.8(2)          10%(2)
Adjusted Earnings(3)                        $11.9+            $14.4            $16.7             19%
Adjusted Diluted EPS(3)                        --             $1.84            $2.18




(1) Excludes the cumulative effect of change in accounting principle, certain
    significant items and merger-related costs.

(2) Adjusted to reflect the elimination of the impact of the COX-2 co-promotion
    agreement.

(3) As defined in Appendix A.

+   Pro forma shown for comparison purposes only; closing anticipated by
    year-end 2002.

                                * * * * * * * * *

Pfizer and Pharmacia will file a proxy statement/prospectus and other relevant
documents concerning the proposed merger transaction with the SEC. INVESTORS ARE
URGED TO READ THE PROXY STATEMENT/PROSPECTUS WHEN IT BECOMES AVAILABLE AND ANY
OTHER RELEVANT DOCUMENTS FILED WITH THE SEC BECAUSE THEY WILL CONTAIN IMPORTANT
INFORMATION. You will be able to obtain the documents free of charge at the
website maintained by the SEC at www.sec.gov. In addition, you may obtain
documents filed with the SEC by Pfizer free of charge by requesting them in
writing from Pfizer Inc., 235 East 42nd Street, New York, New York 10017,
Attention: Investor Relations, telephone: (212) 573-2668. You may obtain
documents filed with the SEC




by Pharmacia free of charge by requesting them in writing from Pharmacia
Investor Relations, Route 206 North, Peapack, New Jersey 07977, or by telephone
at (908) 901-8000.

Pfizer and Pharmacia, and their respective directors and executive officers and
other members of their management and employees, may be deemed to be
participants in the solicitation of proxies from the stockholders of Pfizer and
Pharmacia in connection with the merger. Information about the directors and
executive officers of Pfizer and their ownership of Pfizer shares is set forth
in the proxy statement for Pfizer's 2002 annual meeting of shareholders.
Information about the directors and executive officers of Pharmacia and their
ownership of Pharmacia stock is set forth in the proxy statement for Pharmacia's
2002 annual meeting of stockholders. Investors may obtain additional information
regarding the interests of such participants by reading the proxy
statement/prospectus when its becomes available.