Earnings Per Share

9 Months Ended

Sep. 30, 2011

Earnings Per Share [Abstract]

Earnings Per Share

11. Earnings per share

The following table presents the computation of basic and diluted earnings per share:

	Three Months Ended September 30					Nine Months Ended September 30
	2011			2010		2011		2010
	(in millions of U.S. dollars, except share and per share data)
Numerator:
Net income (loss)	$	(31	)	$	675	$	835	$	2,107
Denominator:
Denominator for basic earnings per share:
Weighted-average shares outstanding		338,385,734			340,218,717		338,139,477		339,527,671
Denominator for diluted earnings per share:
Share-based compensation plans		—			1,636,802		2,733,434		1,314,662
Adjusted weighted-average shares outstanding and assumed conversions		338,385,734			341,855,519		340,872,911		340,842,333
Basic earnings per share	$	(0.09	)	$	1.98	$	2.47	$	6.21
Diluted earnings per share	$	(0.09	)	$	1.97	$	2.45	$	6.18

Excluded from adjusted weighted-average shares outstanding and assumed conversions is the impact of securities that would have been anti-dilutive during the respective periods. For the three months ended September 30, 2011 and 2010, the potential anti-dilutive share conversions were 2,295,260 shares and 204,251 shares, respectively. The potential anti-dilutive share conversions for the nine months ended September 30, 2011 and 2010, were 223,987 shares and 264,312 shares, respectively.