Weighted average number of common shares outstanding:
Basic
145,718,123
146,842,755
Effect of dilutive shares:
–Stock options and awards
864,776
1,257,516
–Convertible preference shares
—
7,547,220
Diluted (1)
146,582,899
155,647,491
Earnings per common share:
Basic
$
0.57
$
1.53
Diluted
$
0.57
$
1.49
(1) Approximately 5 million outstanding stock options and contingently issuable restricted stock units were not dilutive and not included in the weighted-average number of common shares outstanding for the three months ended March 31, 2012. Approximately 8 million weighted-average common shares that are issuable upon conversion of the convertible preference shares were not dilutive and not included in the weighted-average number of common shares outstanding for the three months ended March 31, 2012. Approximately 2 million outstanding stock options and contingently issuable restricted stock units were not dilutive and not included in the weighted-average number of common shares outstanding for the three months ended March 31, 2011.