The following table presents the computation of basic and diluted earnings per common share for the periods indicated:



	Three Months Ended September 30,
(Dollars in millions, except per share amounts)	2016			2015
Net income	$	563		$	581
Less:
Preferred stock dividends	(55		)	(42		)
Dividends and undistributed earnings allocated to participating securities⁽¹⁾	(1		)	—
Net income available to common shareholders	$	507		$	539
Average common shares outstanding (In thousands):
Basic average common shares	388,358			406,612
Effect of dilutive securities: common stock options and common stock awards	4,854			5,555
Diluted average common shares	393,212			412,167
Anti-dilutive securities⁽²⁾	2,166			619
Earnings per Common Share:
Basic	$	1.31		$	1.33
Diluted⁽³⁾	1.29			1.31

	Nine Months Ended September 30,
(Dollars in millions, except per share amounts)	2016			2015
Net income	$	1,550		$	1,404
Less:
Preferred stock dividends	(137		)	(102		)
Dividends and undistributed earnings allocated to participating securities⁽¹⁾	(2		)	(1		)
Net income available to common shareholders	$	1,411		$	1,301
Average common shares outstanding (In thousands):
Basic average common shares	393,959			409,816
Effect of dilutive securities: common stock options and common stock awards	4,454			5,956
Diluted average common shares	398,413			415,772
Anti-dilutive securities⁽²⁾	3,027			675
Earnings per Common Share:
Basic	$	3.58		$	3.18
Diluted⁽³⁾	3.54			3.13

⁽¹⁾Represents the portion of net income available to common equity allocated to participating securities, composed of fully vested deferred director stock and unvested restricted stock that contain non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders.

⁽²⁾Represents common stock options and other equity-based awards outstanding but not included in the computation of diluted average common shares, because their effect was anti-dilutive.

⁽³⁾Calculations reflect allocation of earnings to participating securities using the two-class method, as this computation is more dilutive than the treasury stock method.