7. Earnings per common share

The computations of basic earnings per common share follow:

	Three Months Ended March 31
	2018			2017
	(In thousands, except per share)
Income available to common shareholders:
Net income	$	352,610			348,927
Less: Preferred stock dividends (a)		(18,130	)		(18,237	)
Net income available to common equity		334,480			330,690
Less: Income attributable to unvested stock-based compensation awards		(1,732	)		(2,128	)
Net income available to common shareholders	$	332,748			328,562
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards		149,470			155,463
Less: Unvested stock-based compensation awards		(782	)		(1,036	)
Weighted-average shares outstanding		148,688			154,427

Basic earnings per common share	$	2.24			2.13

(a)Including impact of not as yet declared cumulative dividends.

7. Earnings per common share, continued

The computations of diluted earnings per common share follow:

	Three Months Ended March 31
	2018			2017
	(In thousands, except per share)

Net income available to common equity	$	334,480			330,690
Less: Income attributable to unvested stock-based compensation awards		(1,731	)		(2,123	)
Net income available to common shareholders	$	332,749			328,567
Adjusted weighted-average shares outstanding:
Common and unvested stock-based compensation awards		149,470			155,463
Less: Unvested stock-based compensation awards		(782	)		(1,036	)
Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock		217			522
Adjusted weighted-average shares outstanding		148,905			154,949

Diluted earnings per common share	$	2.23			2.12

GAAP defines unvested share-based awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) as participating securities that shall be included in the computation of earnings per common share pursuant to the two-class method. The Company has issued stock-based compensation awards in the form of restricted stock and restricted stock units which, in accordance with GAAP, are considered participating securities.

Stock-based compensation awards and warrants to purchase common stock of M&T representing 237,584 and 391,764 common shares during the three-month periods ended March 31, 2018 and 2017, respectively, were not included in the computations of diluted earnings per common share because the effect on those periods would have been antidilutive.