Earnings Per Share

Basic earnings per share is computed by dividing earnings available to MasTec’s common shareholders by the weighted average number of common shares outstanding for the period. Diluted earnings per share is computed by dividing earnings by the number of fully diluted shares, which includes the effect of dilutive potential issuances of common shares as determined using earnings from continuing operations. The potential issuance of common shares upon the exercise, conversion or vesting of outstanding stock options and unvested restricted share awards, as calculated under the treasury stock method, as well as shares associated with the Company’s outstanding convertible debt securities, may be dilutive.

The following table provides details underlying the Company’s earnings per share calculations for the periods indicated (in thousands):



	Years Ended December 31,
	2013			2012			2011
Net income attributable to MasTec:
Net income, continuing operations - basic (a)	$	147,492		$	116,639		$	97,454
Interest expense, net of tax, 2009 Convertible Notes	315			311			487
Net income, continuing operations - diluted	$	147,807		$	116,950		$	97,941
Net (loss) income from discontinued operations - basic and diluted (a)	(6,542		)	(9,213		)	8,547
Net income attributable to MasTec - diluted	$	141,265		$	107,737		$	106,488
Weighted average shares outstanding:
Weighted average shares outstanding - basic	76,923			78,275			82,182
Dilutive common stock equivalents	777			883			1,127
Dilutive premium shares, 2011 Convertible Notes	6,395			2,118			2,162
Dilutive shares, 2009 Convertible Notes	806			806			1,245
Weighted average shares outstanding - diluted	84,901			82,082			86,716

(a) Calculated as total net income less amounts attributable to non-controlling interests.

Outstanding Convertibles Notes - Diluted Share Impact

The Company has $215.0 million principal amount of senior convertible notes outstanding, composed of $202.3 million of senior convertible notes issued in 2011 (the "2011 Convertible Notes") and approximately $12.6 million of senior convertible notes issued in 2009 (the "2009 Convertible Notes"). Dilutive shares associated with the 2009 Convertible Notes are attributable to the underlying principal amounts. The number of common shares issuable upon conversion of the Company’s 2009 Convertible Notes is reflected in the calculation of weighted average diluted earnings per share for the corresponding periods by application of the “if-converted” method to the extent their effect on the computation of earnings per share from continuing operations is dilutive. Under the “if-converted” method, net income from continuing operations is adjusted to add back the after-tax amount of interest recognized in the period associated with the convertible notes, and correspondingly, the convertible notes are assumed to have been converted with the resulting common shares added to weighted average shares outstanding. Due to the optional cash settlement feature and the Company's intent to settle the principal amount in cash, the conversion shares underlying the outstanding principal amount of the 2011 Convertible Notes, totaling approximately 13.0 million shares, are not required to be included in the Company's diluted share count. If, however, the average price per share of the Company's common stock exceeds the respective conversion prices of the 2011 Convertible Notes, the resulting amount, in shares, of any premium is required to be included in the Company's diluted share count, also referred to as premium shares. The number of premium shares included in our diluted share count will vary with fluctuations in our share price. Higher actual share prices result in a greater number of premium shares. As the Company’s weighted average stock price for the years ended December 31, 2013, 2012 and 2011 exceeded the conversion prices of the 2011 Convertible Notes, dilutive premium shares have been included in the Company's share count for the corresponding periods.

The 2011 Convertible Notes consist of $105.3 million principal amount of 4.0% senior convertible notes, convertible at $15.76 per share (the "2011 4.0% Notes") and $97.0 million principal amount of 4.25% senior convertible notes, convertible at $15.48 per share (the "2011 4.25% Notes"). The calculations underlying the number of premium shares included in the Company’s diluted share count for the periods indicated are as follows (in thousands, except per share amounts):



	As of and for the Years Ended December 31,
	2013				2012				2011
Premium Share Information:	2011 4.0% Notes		2011 4.25% Notes		2011 4.0% Notes		2011 4.25% Notes		2011 4.0% Notes		2011 4.25% Notes
Number of conversion shares, principal amount	6,683		6,268		6,683		6,268		6,683		6,268
Weighted average actual per share price	$	30.86	$	30.86	$	18.68	$	18.68	$	18.90	$	18.88
Weighted average premium value	$	100,911	$	96,423	$	19,494	$	20,064	$	20,968	$	21,319
Weighted average equivalent premium shares	3,270		3,125		1,044		1,074		1,067		1,095

Diluted Shares, Other Information

For the year ended December 31, 2013, there were no anti-dilutive common stock equivalents. For the years ended December 31, 2012 and 2011, a total of 8,313 and 9,479 weighted average anti-dilutive common stock equivalents were not included in the Company’s diluted earnings per share calculations, respectively.