($ in millions, except per share data)

Three months ended
September 30,

Nine months ended
September 30,

2011

2010

2011

2010

Numerator:

Net income

$

165

$

367

$

64

$

632

Denominator:

Weighted average common shares outstanding

512.0

540.9

520.4

540.6

Effect of dilutive potential common shares:

Stock options

1.6

1.9

2.0

Restricted stock units (non-participating)

0.6

0.2

0.5

0.1

Weighted average common and dilutive potential common shares outstanding

514.2

543.0

522.9

542.7

Earnings per share - Basic

$

0.32

$

0.68

$

0.12

$

1.17

Earnings per share - Diluted

$

0.32

$

0.68

$

0.12

$

1.16