##### 



Exhibit 10(aa)



| |                                 
| | --------------------------------
| | PCS Supplemental Retirement Plan
| | for U.S. Executives             
|
| | January 1, 1999                 





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|                                              |  |                                             |  |  
|--------------------------------------------- |  | ------------------------------------------- |  | -
|Contents                                      |  |                                            
|                                             
|                                             
|Article 1.  Establishment and
    Purpose     |  | 1                                          
|1.1                                           |  | Establishment                               |  | 1
|1.2                                           |  | Purpose                                     |  | 1
|Article 2.  Definitions and
    Construction  |  | 1                                          
|2.1                                           |  | Definitions                                 |  | 1
|2.2                                           |  | Gender and Number                           |  | 4
|2.3                                           |  | Severability                                |  | 4
|2.4                                           |  | Transfer of Employment                      |  | 4
|2.5                                           |  | Successors                                  |  | 4
|2.6                                           |  | Applicable Law                              |  | 5
|Article 3.  Eligibility and
    Participation |  | 5                                          
|3.1                                           |  | Eligibility                                 |  | 5
|3.2                                           |  | Cessation of Participation                  |  | 5
|Article 4.  Retirement
    Benefit            |  | 5                                          
|4.1                                           |  | Vesting and Forfeiture of Benefits          |  | 5
|4.2                                           |  | Amount of Benefit                           |  | 6
|4.3                                           |  | Timing and Manner of Payment                |  | 6
|4.4                                           |  | Tax Withholding                             |  | 6
|4.5                                           |  | Nontransferability                          |  | 6
|Article 5.  Preretirement Death
    Benefit   |  | 6                                          
|5.1                                           |  | Entitlement and Amount of the Death Benefit |  | 6
|5.2                                           |  | Timing and Manner of Payment                |  | 7
|Article 6.  Funding                           |  | 7                                          
|6.1                                           |  | Unfunded Plan                               |  | 7
|6.2                                           |  | Costs of the Plan                           |  | 7
|Article 7.  Rabbi
    Trust                   |  | 7                                          
|7.1                                           |  | Establishment                               |  | 7
|7.2                                           |  | Terms                                       |  | 8
|7.3                                           |  | Funding                                     |  | 8
|7.4                                           |  | Distributions                               |  | 8



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|                                          |  |                            |  |  
|----------------------------------------- |  | -------------------------- |  | -
|Article 8.  Administration                |  | 8                         
|8.1                                       |  | The Committee              |  | 8
|8.2                                       |  | Authority of the Committee |  | 8
|8.3                                       |  | Decisions Binding          |  | 8
|Article 9.  Amendment and
    Termination |  | 9                         



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Article 1.     Establishment
and Purpose

1.1     Establishment

Potash Corporation of Saskatchewan Inc.
(Company), a corporation under the laws of Canada,
pursuant to a resolution of its Board of Directors, established
as of January 1, 1999, a supplemental executive retirement
plan for key employees to be known as the PCS Supplemental
Retirement Plan for U.S. Executives
(Plan).

1.2     Purpose

This Plan is intended to fully restore pension
benefits under a tax-qualified pension plan that would otherwise
have been provided to a select group of eligible employees in
the absence of certain restrictions imposed by the Internal
Revenue Code. This Plan supersedes all other restoration plans
covering the Participants under this Plan. The Plan is intended
to be a plan within the meaning of section 201(2) of the
Employee Retirement Income Security Act of 1974, as amended,
that is unfunded and maintained primarily for the purpose of
providing deferred compensation for a select group of management
or highly compensated employees (top-hat plan).

Article 2.     Definitions
and Construction

2.1     Definitions

The following terms shall have the meaning stated
below and, when intended, such terms shall be capitalized.



|    |                      
|--- | ---------------------
|(a) | Actuarial Equivalent.



| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (1) | In General.The term
    Actuarial Equivalent or Actuarially
    Equivalent means a benefit payable at a particular time
    and in a particular form under which the aggregate payments
    expected to be received are equal in value to the aggregate
    payments expected to be received at a different time or in a
    different form of benefit. The actuarial assumptions used by the
    Pension Plan to calculate a Participants benefit shall be
    used for this Plan.



| |                                                                                                
| | -----------------------------------------------------------------------------------------------
| | In the absence of specified actuarial
    assumptions, the following assumptions shall be used:



| |     |                                                                                                                                                                
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (A) | the 1994 Unisex Pension Table with male annuity
    factors weighted at fifty percent (50%) and female annuity
    factors weighted at fifty percent (50%); and
|
| | (B) | an interest rate of eight percent (8%)
    per year.                                                                                                           



| |     |                                                                                                                                                                                                                                                                                                                                                                                                                     
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (2) | Lump Sum Benefits.Notwithstanding anything to the
    contrary, in determining an Actuarially Equivalent lump sum
    benefit, the IRS Interest Rate and the IRS Mortality Table shall
    be used. The conversion of the amount of a benefit that is
    described as an amount payable in an annuity form to an amount
    payable as a lump sum benefit shall be made after the amount of
    the annuity form is

1



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| |     |                                                                                                                                                                                   
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     | adjusted pursuant to the actuarial factors of the
    Pension Plan to reflect commencement of benefits at a date other
    than the normal retirement date under the Pension Plan.
|
| | (3) | Definitions.                                                                                                                                                                      



| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (A) | IRS Interest Rate.The term IRS Interest Rate
    means the average yield for the thirty (30) year Treasury
    Constant Maturities (or such successor rate that may be
    specified under Code section 417 for lump sum calculations
    unless the Committee determines otherwise) for the second month
    before the month the Participant terminates employment from all
    Employers and Related Organizations, or if earlier, for the
    second month before the month of the Participants death
    (whether or not the benefit distribution occurs later).
|
| | (B) | IRS Mortality Table.The term IRS Mortality
    Table means the mortality table prescribed by the Internal
    Revenue Service that is based on the prevailing
    commissioners standard table used to determine reserves
    for group annuity contracts issued on the date the Participant
    terminates employment from all Employers and all Related
    Organizations, or if earlier, on the date of the
    Participants death.                                                                                                                              



|    |                                                                                                                                                                                         
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(b) | Board.The term
    Board means the Board of Directors of
    the Company.                                                                                                             
|   
|(c) | Cause.The term
    Cause means the occurrence of one or more of the
    following as determined solely by the Committee in the exercise
    of its good faith and reasonable judgment:



| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (1) | The willful and continued failure by a
    Participant to substantially perform his or her duties with his
    or her Employer or a Related Organization, other than a failure
    resulting from the Participants Disability, followed by
    the failure of the Participant to remedy such failure within ten
    (10) business days after written notice is delivered to the
    Participant. Such notice shall specifically identify the manner
    in which the Committee believes that the Participant has not
    substantially performed his or her duties.
|
| | (2) | Willful gross misconduct by the Participant that
    materially and demonstrably injures his or her Employer or a
    Related Organization monetarily or in any other manner. However,
    a Participants act or failure to act shall not be
    considered willful if the Participants act or
    failure was in good faith and based on a reasonable belief that
    his or her act or omission was in the best interest of his or
    her Employer and its Related Organizations.                                                                            



|    |                                                                                              
|--- | ---------------------------------------------------------------------------------------------
|(d) | Change in Control.The term Change in Control
    means one or more of the following events:

2



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| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (1) | Within any period of two (2) consecutive
    years, the directors of the Board at the beginning of such
    period and any new directors cease for any reason to constitute
    a majority of the Board. For the purpose of this paragraph, the
    term new directors means those directors whose
    appointment by the Board or nomination for election by
    shareholders of the Company was approved by a vote of a majority
    of the directors then still in office who either were directors
    at the beginning of the period or whose appointment or
    nomination for election was previously so approved.                                                                                                
|
| | (2) | An amalgamation, merger, consolidation, windup,
    reorganization, or restructuring of the Company with or into any
    other entity occurs, or a similar event (or series of events)
    occurs. However, this paragraph shall not apply if the persons
    who were holders of the Companys securities immediately
    before the event beneficially own (directly or indirectly) after
    the event securities of the surviving (or consolidated)
    corporation representing fifty percent (50%) or more of the
    combined voting power of the surviving corporations
    securities in substantially the same proportions as their
    ownership in the Companys securities immediately before
    such event.



| |                                                                                                                                                                                                                           
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | For the purpose of this paragraph, the term
    securities means those outstanding securities
    entitled to vote in the election of directors of the Company or
    the surviving corporation, whichever is indicated.



| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                         
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (3) | In one transaction or series of transactions
    within any twelve (12) month period, fifty percent (50%) or
    more of the value of the fixed assets of the Company are sold or
    otherwise disposed of (by liquidation, dissolution, dividend, or
    otherwise). The value of the fixed assets shall be based on book
    value as shown on the most recent available audited annual or
    unaudited quarterly consolidated financial statements.
|
| | (4) | Any party, including persons acting jointly or in
    concert with that party, becomes (through a take-over bid or
    otherwise) the beneficial owner, directly or indirectly, of
    securities of the Company representing twenty percent (20%) or
    more of the combined voting power of the Companys
    then-outstanding securities entitled to vote in the election of
    directors of the Company.                                          



|    |                                                                                                                                                                 
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------
|(e) | Code.The term
    Code means the Internal Revenue Code of 1986,
    as amended.                                                                               
|   
|(f) | Committee.The term
    Committee means the Compensation Committee of the
    Board, or any other committee designated by the Board to
    administer the Plan.
|   
|(g) | Company.The term
    Company means Potash Corporation of Saskatchewan
    Inc., or any successor.                                                             
|   
|(h) | Disability.The term
    Disability has the meaning given by the long-term
    disability plan maintained by a Participants Employer.                         

3



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|    |                                                                                                                                                               
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------
|(i) | Effective Date.The
    term Effective Date means January 1, 1999.                                                                                           
|   
|(j) | Employer.The term
    Employer has the meaning given by the
    Pension Plan.                                                                               
|   
|(k) | ERISA.The term
    ERISA means the Employee Retirement Income Security
    Act of 1974, as amended.                                                         
|   
|(l) | Participant.The
    term Participant means an individual who satisfies
    the requirements of section 3.1 or who has an accrued
    benefit under the Plan.
|   
|(m) | Pension Plan.The
    term Pension Plan means the PCS
    U.S. Employees Pension Plan, or a predecessor or
    successor plan.                              
|   
|(n) | Plan.The term
    Plan means the PCS Supplemental Retirement Plan for
    U.S. Executives.                                                                  
|   
|(o) | Plan Year.The term
    Plan Year means the consecutive twelve
    (12) month period beginning each January 1 and ending
    December 31.                    
|   
|(p) | Related Organization.The term Related
    Organization has the same meaning as in the Pension Plan.                                                         
|   
|(q) | Vesting Service.The
    term Vesting Service has the same meaning as in the
    Pension Plan.                                                               

2.2     Gender and
Number

Except when otherwise indicated by the context,
masculine terminology shall include the feminine, and singular
terminology shall include the plural.

2.3     Severability

If any provision of the Plan shall be held
illegal or invalid for any reason, the illegality or invalidity
shall not affect the remaining parts of the Plan, and the Plan
shall be construed and enforced as if the illegal or invalid
provision had not been included.

2.4     Transfer of
Employment

Notwithstanding anything to the contrary, the
transfer of employment of a Participant between his or her
Employer and its Related Organizations shall not be deemed a
termination of the Participants employment with the
Company or a Related Organization for the purposes of
this Plan.

2.5     Successors

All obligations under the Plan of the Company and
the Employers shall be binding upon their successors, whether
the existence of such successor is the result of a direct or
indirect purchase, merger, consolidation, or otherwise, of all
or substantially all of their business or assets.

4



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2.6     Applicable
Law

To the extent not preempted by federal law, the
Plan shall be governed by and construed in accordance with the
laws of the state of Illinois without giving effect to
principles of conflicts of laws.

Article 3.     Eligibility
and Participation

3.1     Eligibility

An individual shall be eligible to participate in
this Plan if 



|    |                                                                                                                                                                                                                                                            
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | the individuals benefit under the Pension
    Plan is reduced on account of Code
    section 401(a)(17) (relating to the amount of
    compensation that may be taken into account) or Code
    section 415 (relating to the maximum permissible benefit),
|   
|(b) | the individual is a management or highly
    compensated employee of his or her Employer or a Related
    Organization, and                                                                                                                                
|   
|(c) | the Committee approves the individuals
    participation in the Plan.                                                                                                                                                                                     

3.2     Cessation of
Participation

The Committee may determine that a Participant is
ineligible to continue participation in the Plan for any reason.
Except as provided in section 4.1(b)(2) (forfeiture
for Cause), such Participants shall retain all rights
relating to benefits previously accrued and vested under
the Plan.

Article 4.     Retirement
Benefit

4.1     Vesting and
Forfeiture of Benefits



|    |                                                                                                          
|--- | ---------------------------------------------------------------------------------------------------------
|(a) | Vesting.A
    Participant shall become fully vested in benefits under the Plan
    upon the earliest of 



| |     |                                                                                                                       
| | --- | ----------------------------------------------------------------------------------------------------------------------
| | (1) | the date that the Participant is at least age
    fifty-five (55) with at least five (5) years of Vesting
    Service,
|
| | (2) | the Participants Disability, or                                                                                      
|
| | (3) | a Change in Control of the Company.                                                                                   



|    |            
|--- | -----------
|(b) | Forfeiture.



| |     |                                                                                                                                                   
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------
| | (1) | In General.A
    Participant shall forfeit all benefits under the Plan if, before
    vesting as provided in subsection (a), the
    Participant 



| |     |                                                                                                                                                       
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------
| | (A) | is removed from participation in the Plan for any
    reason, or                                                                                      
|
| | (B) | terminates employment with all Employers and all
    Related Organizations for any reason (other than death after
    vesting under the Pension Plan).

5



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| |     |                                                                                                                                                                                                                                                                                                                                                   
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | (2) | For Cause.Notwithstanding anything to the
    contrary in this Plan, whether or not the Participant has vested
    under subsection (a), if the Participants employment is
    terminated for Cause, the Participant and the Participants
    beneficiaries shall immediately forfeit all rights and
    entitlement to benefits under the Plan.

4.2     Amount of
Benefit

The amount of a Participants benefit shall
equal the amount of the lump sum Actuarial Equivalent of a
monthly benefit equal to the excess (if any) of (a) over
(b) where 



|    |                                                                                                                                                                                                  
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | is the monthly benefit that the Participant would
    have accrued under the Pension Plan had the monthly benefit been
    determined without regard to Code sections 401(a)(17) and
    415, and
|   
|(b) | is the monthly benefit that the Participant
    actually accrued under the Pension Plan.                                                                                                         

Unless the Committee determines otherwise, in
computing the monthly benefit under this section, no benefit
shall accrue for the period of service with White Spring
Agricultural Chemicals, Inc. before November 1, 1995; with
the Arcadian Corporation before March 1, 1997; or with PCS
Sales (USA), Inc. before January 1, 1999.

4.3     Timing and
Manner of Payment

A Participants benefit under
section 4.2 shall be payable in a lump sum amount as of the
annuity starting date under the Pension Plan. The Participant
may not defer payment of the benefit to a later date and may not
elect another form of payment.

4.4     Tax
Withholding

A Participants Employer shall have the
right to require that Participants remit to it an amount
sufficient to satisfy federal, state, and local tax withholding
requirements, or to deduct from all payments made pursuant to
the Plan amounts sufficient to satisfy such withholding
requirements.

4.5     Nontransferability

A Participants rights to benefits under the
Plan may not be sold, transferred, assigned, or otherwise
alienated or hypothecated. No payment shall be made under the
Plan to any assignee or creditor of a Participant or to any
assignee or creditor of a Participants beneficiary.

Article 5.     Preretirement
Death Benefit

5.1     Entitlement
and Amount of the Death Benefit

If a Participant dies after vesting under the
Pension Plan but before the annuity starting date under the
Pension Plan, the Participants beneficiary under the
Pension Plan shall be entitled to a benefit equal to the lump
sum Actuarial Equivalent of the excess of (a) over
(b) where 

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|    |                                                                                                                                                                                                                         
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | is the amount of the preretirement death benefit
    that would be payable to the beneficiary under the terms of the
    Pension Plan determined on the basis of the monthly amount
    described in section 4.2(a), and
|   
|(b) | is the amount of the preretirement death benefit
    that is payable to the beneficiary under the Pension Plan.                                                                                                         

5.2     Timing and
Manner of Payment

The death benefit described in section 5.1
shall be payable as a lump sum amount as of the annuity starting
date for the death benefit that is payable under the
Pension Plan.

The payment of the death benefit under this
Article shall fully discharge the Plans obligation under
the Plan to all persons with respect the Participants
benefit.

Article 6.     Funding

6.1     Unfunded
Plan



|    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | In General.The Plan
    shall not be funded for the purposes of the Code and ERISA. The
    obligation of the Participants Employer under the Plan
    shall be that of an unfunded and unsecured promise to pay money
    in the future.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|   
|(b) | Unsecured General Creditors.Participants and their beneficiaries,
    heirs, successors, and assigns shall have no secured legal or
    equitable right, interest, or claim in any property or asset of
    any Employer or any Related Organization, nor shall they be
    beneficiaries of, or have any right, claim, or interest in any
    life insurance policy, annuity contract, or any proceeds
    therefrom owned or which may be acquired by any Employer or any
    Related Organization. No policy, annuity contract, or any other
    asset of any Employer or any Related Organization shall be held
    under any trust for the benefit of Participants, their
    beneficiaries, heirs, successors or assigns, or held in any way
    as collateral security for fulfilling the obligations of any
    Employer or Related Organization under the Plan. All assets and
    policies of the Employers and the Related Organizations shall be
    their general, unpledged, unrestricted assets.

6.2     Costs of the
Plan

Except as provided in Article 7 (rabbi
trust), all costs of implementing and administering the Plan and
paying the benefits of the Plan shall be borne by the
Participants Employer.

Article 7.     Rabbi
Trust

7.1     Establishment

The Committee may, at its sole and absolute
discretion, at any time after the Effective Date, establish an
irrevocable rabbi trust that is a grantor trust within the
meaning of Code sections 671-677 for the benefit of
Participants and beneficiaries of Participants. Such a trust
shall have an independent trustee, selected by the Committee,
who shall have fiduciary duty to carry out the terms and
conditions of the Plan.

7



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The provisions of this Article shall apply only
if the Committee exercises its discretion and establishes a
rabbi trust.

7.2     Terms

The assets of the rabbi trust shall be subject to
the claims of general creditors in the event of a bankruptcy or
insolvency under such terms that are specifically defined by the
provisions of the rabbi trust and under a required procedure for
notifying the trustee of any such bankruptcy or insolvency.

7.3     Funding



|    |                                                                                                                                                                                                                                                                                                    
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | In General.Except
    as provided in subsection (b), at the sole and absolute
    discretion of the Committee, the Participants Employer
    shall contribute cash to the rabbi trust for the benefit of the
    Participant and his or her beneficiaries, as the Committee deems
    appropriate.
|   
|(b) | Change in Control.If a Change in Control occurs, the
    rabbi trust shall be funded immediately with an amount equal to
    the Actuarial Equivalent of the benefits under the Plan. The
    Companys actuary shall determine the amount to
    be funded.                                       

7.4     Distributions

Following a Change in Control, distributions of a
Participants benefits shall be made from the rabbi trust
directly to the Participant or the Participants
beneficiary in accordance with Article 4 or Article 5
(as the case may be).

To the extent any benefits provided under the
Plan are actually paid from the rabbi trust, the Employer shall
have no further obligation for the benefit to the extent so
paid, but to the extent not so paid, such benefits shall remain
the obligation of, and shall be paid by the Employer.

Article 8.     Administration

8.1     The
Committee

The Committee, or another committee designated by
the Board, shall administer the Plan. The Committee may delegate
any or all of its administrative responsibilities.

8.2     Authority of
the Committee

Except as otherwise provided, the Committee shall
have the full power and discretion to select employees for
participation in the Plan, to determine the terms and conditions
of each employees participation, to construe and interpret
the Plan and any agreement or instrument concerning the Plan, to
establish, amend, or waive procedures for the Plans
administration, and to amend the Plan to the extent permitted
under Article 9. Further, the Committee shall have full
power and discretion to make any other determination that may be
necessary or advisable for the Plans administration.

8.3     Decisions
Binding

All determinations and decisions made by the
Committee or the Board and all related orders or resolutions of
the Committee or the Board shall be final, conclusive, and
binding on all

8



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##### 



persons, including the Company, Employers,
Related Organizations, Employees, and their estates and
beneficiaries.


Article 9.     Amendment
and Termination

The Board reserves the right to amend, modify, or
terminate the Plan at any time for any reason. Such right shall
be exercised only by a written resolution or other written
instrument approved by the Board.

The Committee shall also have the right to amend
the Plan without obtaining the approval of the Board of
Directors if the amendment does not 



|    |                                                                                                                                                                                                                                                                                
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(a) | have the effect of terminating the Plan;                                                                                                                                                                                                                                       
|   
|(b) | materially increase the cost of providing
    benefits under the Plan, unless the amendment conforms the Plan
    with legislation, governmental regulations, rules, or
    interpretive bulletins expressing a public policy or condition
    with which the Plan must comply;
|   
|(c) | revise this Article to increase the
    Committees authority to amend the Plan or derogate from
    the authority of the Board of Directors; and                                                                                                                              
|   
|(d) | confer any special advantage whether economic or
    otherwise, whether present or contingent, on the Committee or
    its members.                                                                                                                                            

The Committee may exercise its right to amend the
Plan only by a written resolution or other written instrument
approved by the Committee.

No amendment or termination may adversely affect
the rights or benefits of a Participant previously accrued and
vested under the Plan without the consent of
the Participant.

* * * * * * * * * *

In Witness Whereof,the duly authorized officers of Potash
Corporation of Saskatchewan Inc. have executed this instrument
as of January 1, 1999 on August 9, 2002.

| |  |  |  |                                             |  |                                     
| |  |  |  | ------------------------------------------- |  | ------------------------------------
| |  |  |  | Potash Corporation of
    Saskatchewan Inc.
| |  |  |  | By                                          |  | WILLIAM J. DOYLE                    
| |  |  |  |                                             |  |                                     
| |  |  |  |                                             |  | President & CEO                     
|
| |  |  |  |                                             |  | BARBARA JANE IRWIN                  
| |  |  |  |                                             |  |                                     
| |  |  |  |                                             |  | Senior Vice President Administration
|
| |  |  |  |                                             |  | (Corporate Seal)                    

9