Supplemental Retirement Benefit Letter - Monsanto Corp, Pharmacia Corp. and R. William Ide III


                                 May 3, 2000


R. William Ide III, Esq.
Monsanto Company
800 North Lindbergh Boulevard
St. Louis, MO 63167

Dear Bill:

         The purpose of this letter is to memorialize certain determinations
made by the People Committee of the Board of Directors ("Committee") of
Monsanto Company, now known as Pharmacia Corporation ("Company"), at its
October 23, 1997 meeting. The Committee reviewed the retirement benefits
made available to you under the Monsanto Company Pension Plan ("Pension
Plan"), the Monsanto Company ERISA Parity Pension Plan ("Parity Pension
Plan"), and the Monsanto Company Supplemental Retirement Plan ("Supplemental
Plan"). In recognition of the experience and expertise you have brought to
the Company and your potential service with the Company, the Committee
determined to award you, subject to certain conditions, a "Supplemental
Retirement Benefit" designed to produce a total retirement benefit from the
Company at age 65 comparable to that which a Company employee with 30 years
of service would receive (taking into account the value of any pension
benefits earned as an active employee of the Company and pension benefits
received from prior employers). The value of Supplemental Retirement Benefit
will be credited to a notional bookkeeping account (the "SERP Account") and
will be equal to:

         (a)      Three times the sum of the Contribution Credits that would
                  have been credited to you under the Pension Plan had the
                  cash balance plan formula in the Pension Plan been in
                  effect as of the date of your employment, such amount to
                  be credited to you under the terms of the Pension Plan and
                  the Parity Pension Plan as in effect as of January 1, 1997
                  with respect to your Compensation between the date of your
                  employment with the Company and December 31, 1997; plus
                                                                     ----
         (b)      Three times the sum of the Contribution Credits credited
                  to you under the Pension Plan and the Parity Pension Plan
                  with respect to each calendar year during which you are
                  employed by the Company, commencing with calendar year
                  1997 and continuing through the calendar year in which you
                  attain age 65 or terminate employment with the Company,
                  whichever shall first occur; plus
                                               ----

R. William Ide III, Esq.
May 2, 2000
Page 2

         (c)      Interest on your SERP Account balance credited as of the
                  first day of each month during which you are employed by
                  the Company at a rate equal to the "Interest Rate" as
                  defined in the Pension Plan.

         The balance of your SERP Account from time to time shall be deemed
to your "Supplemental Retirement Benefit." Except as specifically provided
below, you will be fully vested in your Supplemental Retirement Benefit at
all times.

         The optional payment form you elect under the Parity Pension Plan
will also apply to payment of your Supplemental Retirement Benefit, using
the same actuarial factors as are used under the Parity Pension Plan.
Interest will be credited to your Supplemental Retirement Benefit beginning
as of the date of your termination of employment and ending as of the date
payment of the benefit commences at the same rate as provided under the
Parity Pension Plan.

         If you die while employed by the Company or any of its affiliates,
are married, and your spouse survives you, she will be entitled to receive a
survivor's benefit in an amount equal to the value of your Supplemental
Retirement Benefit at the time of your death. Your spouse may elect to have
such amount paid in any manner available to a beneficiary under the Parity
Pension Plan.

         You may request deferral of the payment of your Supplemental
Retirement Benefit if you submit a timely request prior to termination of
employment in accordance with the deferral procedures set forth in the
Parity Pension Plan. The Committee will consider your deferral request, and
if it is approved, you will be permitted to defer payment of your
Supplemental Retirement Benefit on the same terms and conditions as
permitted with respect to your benefit under the Parity Pension Plan.

         This Supplemental Retirement Benefit will be separate from and in
addition to any pension benefit you are entitled to receive under the
Pension Plan, Parity Pension Plan and Supplemental Plan.

         The Supplemental Retirement Benefit may not be assigned by you, and
any attempted assignment, pledge or other transfer shall be void. If any
court, agency, or other party orders or is otherwise successful in obtaining
an order for transfer in whole or in part of the Supplemental Retirement
Benefit, it shall thereupon be deemed automatically terminated in full.

         The Supplemental Retirement Benefit and the Company's obligations
hereunder may be terminated in whole or in part at any time by the Committee
(or its successor) if, after your employment with the Company, any of its
affiliates, or the assignee of this agreement ends, you become employed by
or are retained in any manner by an agricultural, pharmaceutical or other
company in competition with any of the companies.

         Any term capitalized but not defined herein shall have the meaning
assigned to it in the Pension Plan. To the extent necessary, the Pension
Plan and the Parity Pension Plan are incorporated by reference herein and
made a part hereof.


R. William Ide III, Esq.
May 2, 2000
Page 3

         Please acknowledge your receipt and acceptance of this agreement by
signing both copies of this letter and returning one copy to my office.

                                          Very truly yours,

                                          PHARMACIA CORPORATION


                                          By /s/ John Murabito
                                             -----------------

                                          Its VP, Ag HR    5/12/00


Received and Acknowledged:

/s/ R. William Ide III
----------------------
R. William Ide III

Date: May 3, 2000
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