**Exhibit 10(cc)****2005 PERFORMANCE OPTION PLAN****1.**     **Purpose of Plan**     Potash Corporation of Saskatchewan Inc. (the “Corporation”) by resolution of its Board ofDirectors (the “Board”) has established, subject to shareholder approval at the Corporation’s 2005Annual and Special Meeting of shareholders, this Potash Corporation of Saskatchewan Inc. 2005Performance Option Plan (the “Plan”) to support the Corporation’s compensation philosophy ofproviding selected employees and officers with an opportunity to: promote the growth andprofitability of the Corporation; align their interests with shareholders; and, earn compensationcommensurate with corporate performance. The Corporation believes this Plan will directly assist insupporting the Corporation’s compensation philosophy by providing participants with the opportunitythrough stock options, which will vest, if at all, based on corporate performance over a three-yearperiod, to acquire Common Shares of the Corporation (“Common Shares”).**2.**     **Duration of this Plan**     This Plan was adopted by the Board on February 28, 2005 to be effective as of January 1, 2005(the “Effective Date”), subject to shareholder approval at the Corporation’s 2005 Annual andSpecial Meeting of shareholders, and shall remain in effect, unless sooner terminated as providedherein, until one (1) year from the Effective Date, at which time it will terminate. After thisPlan is terminated, no stock options may be granted but stock options previously granted shallremain outstanding in accordance with their applicable terms and conditions and this Plan’s termsand conditions.**3.**     **Administration**     This Plan shall be administered by the Compensation Committee of the Board or any othercommittee designated by the Board to administer this Plan (the “Committee”). The Committee shall beresponsible for administering this Plan, subject to this Section 3 and the other provisions of thisPlan. The Committee may employ attorneys, consultants, accountants, agents, and other individuals,any of whom may be an employee, and the Committee, the Corporation, and its officers and directorsshall be entitled to rely upon the advice, opinions, or valuations of any such individuals. Allactions taken and all interpretations and determinations made by the Committee shall be made in theCommittee’s sole discretion and shall be final and binding upon the participants, the Corporation,and all other interested individuals.**4.**     **Authority of the Committee**     The Committee shall have full and exclusive discretionary power to interpret the terms and theintent of this Plan and any Stock Option Award Agreement or other agreement or document ancillaryto or in connection with this Plan, to determine eligibility for stock options and to adopt suchrules, regulations, forms, instruments, and guidelines for administering this Plan as the Committeemay deem necessary or proper. Such authority shall include adopting modifications and amendments toany Stock Option Award Agreement that are necessary to comply with the laws of the countries andother jurisdictions in which the Corporation and/or its subsidiaries operate.**5.**     **Shares Subject to Stock Options**     The aggregate number of Common Shares issuable after February 28, 2005 pursuant to stockoptions under this Plan may not exceed 1,200,000 Common Shares. The aggregate number of CommonShares in respect of which stock options have been granted to any one person pursuant to this Planand which remain outstanding shall not at any time exceed 300,000. The authorized limits under thisPlan shall be subject to adjustment under Sections 12 and 13.     If any stock option granted under this Plan, or any portion thereof, expires or terminates forany reason without having been exercised in full, the Common Shares with respect to which suchoption has not been exercised shall again be available for further stock options under this Plan;provided, however, that anystock option that is granted under this Plan that does not vest as a result of a failure tosatisfy the Performance Measures, shall not be again available for grant under this Plan.
 

 
**6.**     **Grant of Stock Options**     From time to time the Board may designate individual officers and employees of the Corporationand its subsidiaries eligible to be granted options to purchase Common Shares and the number ofCommon Shares which each such person will be granted a stock option to purchase; provided that theaggregate number of Common Shares subject to such stock options may not exceed the number providedfor in Section 5 of this Plan. Non-employee directors and other non-employee contractors and thirdparty vendors are not eligible to participate in this Plan.**7.**     **Option Price**     The option price for any option granted under this Plan to any optionee shall be fixed by theBoard when the option is granted and shall be not less than the fair market value of the CommonShares at such time which, for optionees resident in the United States and any other optioneesdesignated by the Board, shall be deemed to be the closing price per Common Share on the New YorkStock Exchange on the last trading day immediately preceding the day the option is granted and, forall other optionees, shall be deemed to be the closing price per Common Share on the Toronto StockExchange on the last trading day immediately preceding the day the option is granted; providedthat, in either case, if the Common Shares did not trade on such exchange on such day the optionprice shall be the closing price per share on such exchange on the last day on which the CommonShares traded on such exchange prior to the day the option is granted.**8.**     **Vesting of Stock Options**     Subject to achievement of Performance Measures as certified and approved by the AuditCommittee of the Board, stock options granted under this Plan will vest no later than thirty (30)days after the audited financial statements for the applicable Performance Period have beenapproved by the Board.**9.**     **Performance Measures for Vesting of Stock Options**(a) The Performance Measures which will be used to determine the degree to which stock optionswill vest over the three-year period beginning the first day of the fiscal year in which theyare granted (the “Performance Period”) shall be cash flow return on investment (“CFROI”) andweighted average cost of debt and equity capital (“WACC”). (i) CFROI is the ratio of after tax operating cash flow to average gross investment overthe fiscal year, calculated as A divided by B, where (1) A equals operating income plusnonrecurring or unusual items plus accrued incentive awards plus depreciation andamortization less cash taxes, and (2) B equals the average of total assets plus accumulateddepreciation plus accumulated amortization less cash and cash equivalents less non interestbearing current liabilities.  (ii) WACC is the weighted average cost of debt and equity capital, calculated as [A timesthe product of B divided by C] plus [D times the product of E divided by C], where (1) Aequals the after-tax market yield cost of debt, (2) B equals the market value of debt lesscash and cash equivalents (3) C equals the market value of debt less cash and cashequivalents, plus the market value of equity, (4) D equals the cost of equity, and (5) Eequals the market value of equity.
 

 
(b) In determining the number of stock options that will actually vest based on the degree towhich the Performance Measures have been attained during the applicable Performance Period,the following chart shall be utilized which shows the three year average excess of CFROI beinggreater than WACC and the respective portion of the stock option that will vest:   ***Performance Measure*** ***Vesting Scale*****3 year average excess of** **% of Stock Option****CFROI > WACC** **Grant Vesting** <0% 0%0.20% 30%1.20% 70%2.20% 90%2.50% 100%(c) In assessing the portion of the stock options that shall vest in accordance with the abovechart, the following shall be done: (i) Each year, the CFROI and WACC will be calculated in accordance with the definitionsherein, based on the audited financial statements and approved by the Audit Committee.  (ii) In each Performance Period, the average of the three fiscal years shall be calculatedby taking the simple average of the individual years’ results.  (iii) The resulting three-year average will then be applied, using the scale above todetermine the number of stock options, if any, that will vest as of the end of thePerformance Period.  (iv) For results falling between the reference points in the chart above, the level ofvesting shall be mathematically interpolated between the reference points.**10.**     **Terms of Stock Options**     The period during which a stock option is exercisable may not exceed 10 years from the datethe stock option is granted, and the Stock Option Award Agreement may contain provisions limitingthe number of Common Shares with respect to which the stock option may be exercised in any oneyear. Each stock option agreement shall contain provisions to the effect that:(a) if the employment of an optionee as an officer or employee of the Corporation or a subsidiaryterminates, by reason of his or her death, or if an optionee who is a retiree pursuant toSection 10(b) dies, the legal personal representatives of the optionee will be entitled toexercise any unexercised vested options, including such stock options that may vest after thedate of death, during the period ending at the end of the twelfth calendar month following thecalendar month in which the optionee dies, failing which exercise the stock options terminate; (b) subject to the terms of Section 10(a) above, if the employment of an optionee as an officeror employee of the Corporation or a subsidiary terminates, by reason of retirement inaccordance with the then prevailing retirement policy of the Corporation or subsidiary, theoptionee will be entitled to exercise any unexercised vested stock options, including suchstock options that may vest after the date of retirement, during the period ending at the endof the 36th month following the calendar month in which the optionee retires, failing whichexercise the stock options terminate; (c) if the employment of an optionee as an officer or employee of the Corporation or a subsidiaryterminates, for any reason other than as provided in Sections 10(a) or (b), the optionee willbe entitled to exercise any unexercised vested stock options, to the extent exercisable at thedate of such event, during the period ending at the end of the calendar month immediatelyfollowing the calendar month in which the event occurs, failing which exercise the stockoptions terminate;
 

 
(d) for greater certainty and for these purposes, an optionee’s employment with the Corporationor a subsidiary shall be considered to have terminated effective on the last day of theoptionee’s actual and active employment with the Corporation or subsidiary whether such day isselected by agreement with the optionee or unilaterally by the Corporation or subsidiary andwhether with or without advance notice to the optionee. For the avoidance of doubt, no periodof notice that is given or ought to have been given under applicable law in respect of suchtermination of employment will be utilized in determining an optionee’s entitlement under thePlan. The employment of an optionee with the Corporation shall be deemed to have terminatedfor all purposes of the Plan if such person is employed by or provides services to a personthat is a subsidiary of the Corporation and such person ceases to be a subsidiary of theCorporation, unless the Committee determines otherwise; and (e) each stock option is personal to the optionee and is not assignable, except (i) as providedin Section 10(a), and (ii) at the election of the Board, a stock option may be assignable tothe spouse, children and grandchildren of the original optionee and to a trust, partnership orlimited liability company, the entire beneficial interest of which is held by one or more ofthe foregoing.     Nothing contained in Sections 10(a), (b) or (c) shall extend the period during which a stockoption may be exercised beyond its stipulated expiration date or the date on which it is otherwiseterminated in accordance with the provisions of this Plan.     If a stock option is assigned pursuant to Section 10(e)(ii), the references in Sections 10(a),(b) and (c) to the termination of employment or death of an optionee shall not relate to theassignee of a stock option but shall relate to the original optionee. In the event of suchassignment, legal personal representatives of the original optionee shall not be entitled toexercise the assigned stock option, but the assignee of the stock option or the legal personalrepresentatives of the assignee may exercise the stock option during the applicable specifiedperiod.**11.**     **Exercise of Stock Options**     Subject to the provisions of this Plan, a vested stock option may be exercised from time totime by delivering to the Corporation at its registered office a written notice of exercisespecifying the number of Common Shares with respect to which the stock option is being exercisedand accompanied by payment in cash or certified cheque in full of the purchase price of the CommonShares then being purchased.**12.**     **Adjustments**     Appropriate adjustments to the authorized limits set forth in Section 5, in the number, classand/or type of Common Shares optioned and in the option price per share, both as to stock optionsgranted or to be granted, shall be made by the Board to give effect to adjustments in the number ofCommon Shares which result from subdivisions, consolidations or reclassifications of the CommonShares, the payment of share dividends by the Corporation, the reconstruction, reorganization orrecapitalization of the Corporation or other relevant changes in the capital of the Corporation.**13.**     **Mergers**     If the Corporation proposes to amalgamate or merge with another body corporate, theCorporation shall give written notice thereof to optionees in sufficient time to enable them toexercise outstanding vested stock options, to the extent they are otherwise exercisable by theirterms, prior to the effective date of such amalgamation or merger if they so elect. The Corporationshall use its best efforts to provide for the reservation and issuance by the amalgamated orcontinuing corporation of an appropriate number of Common Shares, with appropriate adjustments, soas to give effect to the continuance of the stock options to the extent reasonably practicable. Inthe event that the Board determines in good faith that such continuance is not in the circumstancespracticable, it may upon 30 days’ notice to optionees terminate the stock options.
 

 
**14.**     **Change of Control**     If a “change of control” of the Corporation occurs, each then outstanding stock option grantedunder this Plan may be exercised, in whole or in part, even if such option is not otherwiseexercisable by its terms. For purposes of this Plan, a change of control of the Corporation shallbe deemed to have occurred if any of the following occur, unless the Board adopts a plan after theEffective Date of this Plan that has a different definition (in which case such definition shall beapplied), or the Committee decides to modify or amend the following definition through an amendmentof this Plan:(a) within any period of two consecutive years, individuals who at the beginning of such periodconstituted the Board and any new directors whose appointment by the Board or nomination forelection by shareholders of the Corporation was approved by a vote of at least a majority ofthe directors then still in office who either were directors at the beginning of the period orwhose appointment or nomination for election was previously so approved, cease for any reasonto constitute a majority of the Board; (b) there occurs an amalgamation, merger, consolidation, wind-up, reorganization or restructuringof the Corporation with or into any other entity, or a similar event or series of such events,other than any such event or series of events which results in securities of the surviving orconsolidated corporation representing 50% or more of the combined voting power of thesurviving or consolidated corporation’s then outstanding securities entitled to vote in theelection of directors of the surviving or consolidated corporation being beneficially owned,directly or indirectly, by the persons who were the holders of the Corporation’s outstandingsecurities entitled to vote in the election of directors of the Corporation prior to suchevent or series of events in substantially the same proportions as their ownership immediatelyprior to such event of the Corporation’s then outstanding securities entitled to vote in theelection of directors of the Corporation; (c) 50% or more of the fixed assets (based on book value as shown on the most recent availableaudited annual or unaudited quarterly consolidated financial statements) of the Corporationare sold or otherwise disposed of (by liquidation, dissolution, dividend or otherwise) in onetransaction or series of transactions within any twelve month period; (d) any party, including persons acting jointly or in concert with that party, becomes (through atake-over bid or otherwise) the beneficial owner, directly or indirectly, of securities of theCorporation representing 20% or more of the combined voting power of the Corporation’s thenoutstanding securities entitled to vote in the election of directors of the Corporation,unless in any particular situation the Board determines in advance of such event that suchevent shall not constitute a change of control; or (e) the Board approves and/or recommends that shareholders accept, approve or adopt anytransaction that would constitute a change of control under clause b, c or d above anddetermines that the change of control resulting from such transaction will be deemed to haveoccurred as of a specified date earlier than the date under b, c or d, as applicable.**15.**     **Amendment or Discontinuance of this Plan**     The Board may amend or discontinue the Plan at any time, without obtaining the approval ofshareholders of the Corporation unless required by the relevant rules of the Toronto StockExchange, provided that, subject to Sections 12, 13, and 14, no such amendment may increase theaggregate maximum number of Common Shares that may be subject to stock options under this Plan,change the manner of determining the minimum option price, extend the option period under anyoption beyond 10 years, expand the assignment provisions of the Plan, permit non-employee directorsto participate in the Plan or, without the consent of the holder of the option, alter or impair anyoption previously granted to an optionee under this Plan; and, provided further, for greatercertainty, that, without the prior approval of the Corporation’s shareholders, stock options issuedunder this Plan shall not be repriced, replaced, or regranted through cancellation, or by loweringthe option price of a previously granted stock option. Pre-clearance of the Toronto Stock Exchangeof amendments to the Plan will be required to the extent provided under the relevant rules of theToronto Stock Exchange.**16.**     **Evidence of Stock Options**     Each stock option granted under this Plan shall be evidenced by a written stock optionagreement between the Corporation and the optionee which shall give effect to the provisions ofthis Plan and include such other terms as the Committee shall determine (“Stock Option AwardAgreement”).