EARNINGS PER SHARE

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

EARNINGS PER SHARE

EARNINGS PER SHARE

Basic earnings per share are computed by dividing net income by the weighted average common shares outstanding during the periods. Diluted earnings per share are computed by dividing net income by the weighted average common shares and common share equivalents outstanding during the periods. The dilutive effect of common share equivalents is considered in the diluted earnings per share computation using the treasury stock method, which includes consideration of stock-based compensation and convertible debt.

The following table sets forth the details of basic and diluted earnings per share:

	Three Months Ended
	September 30,
	2012		2011
Net income attributable to WESCO International, Inc.	$	63,415	$	53,890
Weighted average common shares outstanding used in computing basic earnings per share	43,705		43,289
Common shares issuable upon exercise of dilutive equity awards	1,032		976
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	6,036		4,206
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	50,773		48,471
Earnings per share attributable to WESCO International, Inc.
Basic	$	1.45	$	1.24
Diluted	$	1.25	$	1.11

	Nine Months Ended
	September 30,
	2012		2011
Net income attributable to WESCO International, Inc.	$	175,267	$	141,402
Weighted average common shares outstanding used in computing basic earnings per share	43,596		43,181
Common shares issuable upon exercise of dilutive equity awards	1,199		1,202
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	6,262		5,400
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	51,057		49,783
Earnings per share attributable to WESCO International, Inc.
Basic	$	4.02	$	3.27
Diluted	$	3.43	$	2.84

For the three and nine months ended September 30, 2012, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded 1.0 million and 1.2 million, respectively, of stock-settled stock appreciation rights at weighted average exercise prices of $64 per share and $62 per share, respectively. These amounts were excluded because their effect would have been antidilutive.

Because of WESCO’s obligation to settle the par value of the 6.0% Convertible Senior Debentures due 2029 (the “2029 Debentures”) and the previously outstanding 1.75% Convertible Senior Debentures due 2026 (the “2026 Debentures” and together with the 2029 Debentures, the “Debentures”) in cash upon conversion, WESCO is not required to include any shares underlying the Debentures in its diluted weighted average shares outstanding until the average stock price per share for the period exceeds the conversion price of the respective Debentures. At such time, only the number of shares that would be issuable (under the treasury stock method of accounting for share dilution) would be included, which is based upon the amount by which the average stock price exceeds the conversion price. The conversion price of the 2029 Debentures is $28.87. Share dilution is limited to a maximum of 11,949,513 shares for the 2029 Debentures. For the three and nine months ended September 30, 2012, the effect of the Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.17 and $0.48, respectively. For the three and nine months ended September 30, 2011, the effect of the Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.11 and $0.35, respectively.