Earnings (Loss) Per Share

12 Months Ended

Sep. 30, 2011

Earnings (Loss) Per Share

9.   Earnings (Loss) Per Share

Below is a reconciliation of weighted average common shares outstanding for purposes of calculating basic and diluted earnings (loss) per share (in thousands, except per share data):

	Year Ended September 30,
	2011		2010		2009
Net income (loss) attributable to Brooks Automation, Inc.	$	128,352	$	58,982	$	(227,858	)
Weighted average common shares outstanding used in computing basic earnings (loss) per share		64,549		63,777		62,911
Dilutive common stock options and restricted stock awards		454		397		—
Weighted average common shares outstanding for purposes of computing diluted earnings (loss) per share		65,003		64,174		62,911
Basic net income (loss) per share attributable to Brooks Automation, Inc. common stockholders	$	1.99	$	0.92	$	(3.62	)
Diluted net income (loss) per share attributable to Brooks Automation, Inc. common stockholders	$	1.97	$	0.92	$	(3.62	)

Approximately 387,000, 888,000 and 1,456,000 options to purchase common stock and 413,000, 187,000 and 1,101,000 shares of restricted stock were excluded from the computation of diluted earnings (loss) per share attributable to Brooks Automation, Inc. common stockholders for the years ended September 30, 2011, 2010 and 2009, respectively, as their effect would be anti-dilutive.