1 Exhibit 11 POTASH CORPORATION OF SASKATCHEWAN INC. COMPUTATION OF PER SHARE EARNINGS FOR THE THREE MONTHS ENDED MARCH 31 (Figures and amounts expressed in thousands, except per share and per option amounts) 2000 1999 -------- -------- A Net income as reported, Canadian GAAP......................... $ 71,626 $ 39,517 B Items adjusting net income.................................... $ (271) - C Net income, US GAAP (A+B)..................................... $ 71,355 $ 39,517 D Weighted average number of shares outstanding................. 53,420 54,249 E Options outstanding to purchase equivalent shares............. 3,734 2,944 F Average exercise price per option............................. $ 64.72 $ 70.36 G Average market price per share................................ $ 50.05 $ 60.08 H Period end market price per share............................. $ 50.00 $ 53.50 I Rate of Return available on option proceeds................... 5.00% 5.00% CANADIAN GAAP Basic earnings per share (A/D)................................ $ 1.34 $ 0.73 Fully diluted earnings per share J Imputed earnings on options proceeds (E*F*I).................. $ 3,021 $ 2,589 Fully diluted earnings per share ((A+J)/(D+E))................ $ 1.31 $ 0.73 UNITED STATES GAAP Basic earnings per share (C/D)................................ $ 1.34 $0.73 Fully diluted earnings per share K Net additional shares issuable (E-(E*F/G)).................... - - Fully diluted earnings per share (C/(D+K)).................... $ 1.34 $ 0.73