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                                                                 Exhibit 10 (mm)

                     POTASH CORPORATION OF SASKATCHEWAN INC.
                               (the "Corporation")

                              Directors' Resolution



WHEREAS the Corporation on May 9, 1991 adopted a supplemental executive
retirement income plan (the "Supplemental Plan") which plan was amended May 9,
1996; and

WHEREAS  it is desirable to amend and restate the Supplemental Plan;


THEREFORE, BE IT RESOLVED:

1.       That the text of the restated and amended plan as set forth in Appendix
         I attached hereto be approved and adopted.

2.       That the actions of the Corporation in adopting the amended and
         restated plan shall not derogate from the rights of any executive
         arising from or pursuant to a written supplemental retirement income
         plan agreement entered into between the executive and the Corporation
         prior to the passing of this resolution.



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                                                                      APPENDIX I


               SUPPLEMENTAL EXECUTIVE RETIREMENT INCOME PLAN-2000

1.       The Corporation shall maintain a supplemental executive retirement
         income plan (the "Supplemental Plan") for persons employed by the
         Corporation in certain executive positions to be designated from time
         to time by the Compensation Committee of the Board of Directors.

2.       The Supplemental Plan shall be unfunded. Any benefits which become
         payable under the Supplemental Plan shall be paid from the general
         assets of the Corporation. The Corporation may purchase a letter of
         credit from a bank or trust company to secure the benefit of one or
         more members.

3.       Designated executives shall not be required nor permitted to contribute
         to the Supplemental Plan.

4.       The normal retirement age under the Supplemental Plan shall be age 65.
         However, members of the Supplemental Plan may begin to receive such
         benefits as early as age 55. Retirement benefits are reduced by 5% for
         each year that the benefit commencement date precedes the executive's
         attainment of age 62.

5.       No benefits are payable under this Supplemental Plan for members who
         leave the Corporation prior to age 55 for any reason.

6.       The annual retirement benefit payable under the Supplemental Plan shall
         be calculated as follows:

         (a)      2% of the executive's average three highest years' earnings

                                multiplied by

                  the executive's years of service with the Corporation as
                  credited under the Potash Corporation of Saskatchewan Inc.
                  Pension Plan (the "Pension Plan") to a maximum of 35

                                    minus

         (b)      the annual retirement benefit which can be provided
                  under the Pension Plan.




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7.       For purposes of the Supplemental Plan only, an executive's earnings
         shall be defined as the executive's annual base pay plus:

         (a)      100% of all bonuses paid or payable in the year to the
                  executive pursuant to the Corporation's annual incentive plan
                  or any similar plan substituted therefor; and

         (b)      any other payment made in a given year to an executive which
                  payment is specifically designated to be included in earnings
                  by the Compensation Committee of the Board of Directors of the
                  Corporation.

8.       (a)      The normal form of the Supplemental Plan provides a reduced
                  initial pension to the executive with 60% of the reduced
                  amount continuing for the life of the executive's spouse (if
                  any) on the executive's death. Optional forms of benefit, such
                  as, but not limited to, providing 60%, 75% and 100% to the
                  spouse, with a corresponding lower initial pension to the
                  executive will also be available.

         (b)      At the direction of the executive supplemental benefits
                  payable under the Plan to the executive shall be paid in a
                  lump sum provided that such benefits shall be actuarially
                  calculated to reflect a cost neutral position to the
                  Corporation.

         (c)      For the purposes of calculating the lump sum payment payable
                  pursuant to paragraph 8(b) the:

                  i)       1983 GAM Mortality Table based on 50/50 unisex; and

                  ii)      annual interest rate on 30 year treasury securities
                           (as published monthly by the United States Federal
                           Reserve and sometimes referred to as the "GATT Rate")
                           for the second month preceding the month of the
                           executive's retirement
                                           or
                           such other mortality table, interest rate, lookback
                           period and stability period as may from time to time
                           be prescribed by the Compensation Committee of the
                           Board of Directors of the Corporation

                  shall be utilized.

9.       Should the executive die after age 55 but prior to retirement from the
         Corporation, the executive's spouse (if any) shall receive the annual
         retirement benefit the spouse would have received had the executive
         retired immediately prior to his or her death and elected a 60%
         survivor pension.


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10.      The proper officers of the Corporation be directed to arrange for the
         appropriate documentation and communication of the Supplemental Plan
         and that the proper officers of the Corporation are further authorized
         to do all other acts and things as may be necessary or desirable to
         implement this resolution.

11.      Any two directors or officers of the Corporation be and are hereby
         authorized to execute on behalf of the Corporation any documentation
         required to establish the Supplemental Plan on the terms and conditions
         as aforesaid.




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May 16, 2000
                                                         PERSONAL & CONFIDENTIAL


Dear :

RE:    Long-Term Incentive Plan (LTIP) and approved amendments to Supplemental
       Retirement Income (SERI) Plan
--------------------------------------------------------------------------------

At its meeting on May 10, 2000, the Board of Directors of PCS approved a new
Long-Term Incentive Plan (LTIP) and also approved amendments to the Supplemental
Executive Retirement Income (SERI) Plan.

The new Long-Term Incentive Plan has changed substantially from the previous
plan and you should be receiving from Mr. Doyle information in that regard.
Among the changes is a provision that the LTIP award be paid in a lump sum at
the end of each three year cycle. Under the previous plan, the award was paid
annually on a 1/6, 1/6, 2/3 basis.

The SERI Plan was modified to define "earnings" as annual base salary plus the
Annual Incentive Plan payment. Prior to the amendments, "earnings" was defined
as annual base salary plus all bonus payments made in a year. As a consequence,
LTIP payments are not included in "earnings" under the amended SERI Plan.

The Compensation Committee of the Board considered the impact of these two
changes on existing SERI participants (of whom you are one). The Committee
concluded that it would "grandfather" existing SERI participants (so that the
amendments regarding the definition of earnings would not affect them) provided
that the participant agrees that payments under the new LTIP be deemed to have
been paid annually on a 1/3, 1/3, 1/3 basis for the purposes of calculating
"earnings" under the SERI Plan.

                                                                      . . . . /2


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Please signify your agreement with the foregoing by signing the enclosed copy of
this letter where indicated and returning it to me. This letter, when signed by
you, will constitute an amendment to your existing SERI contract.

If you have any questions regarding the foregoing, please call me.

Yours truly,

POTASH CORPORATION OF SASKATCHEWAN INC.


/S/ JOHN L.M. HAMPTON


JOHN L. M. HAMPTON
Senior Vice President, General Counsel
and Secretary

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Enclosure