Earnings Per Share

Earnings per share of common stock outstanding were computed as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
	(Millions Except Share and Per Share Amounts)
Basic earnings per share —
Net income attributable to Tenneco Inc.	$	54	$	83	$	162	$	139
Weighted average shares of common stock outstanding	51,272,618		52,508,078		51,247,664		53,265,149
Earnings per share of common stock	$	1.05	$	1.57	$	3.17	$	2.61
Diluted earnings per share —
Net income attributable to Tenneco Inc.	$	54	$	83	$	162	$	139
Weighted average shares of common stock outstanding	51,272,618		52,508,078		51,247,664		53,265,149
Effect of dilutive securities:
Restricted stock, PSUs and RSUs	93,956		89,666		95,022		106,320
Stock options	35,255		89,912		53,241		130,395
Weighted average shares of common stock outstanding including dilutive securities	51,401,829		52,687,656		51,395,927		53,501,864
Earnings per share of common stock	$	1.05	$	1.57	$	3.16	$	2.60

As of September 30, 2018 and 2017, the outstanding options to purchase shares of common stock that were not included in the computation of diluted earnings per share because they were anti-dilutive were 124,865 and 127,359 shares for the three months ended September 30, 2018 and 2017, respectively, and 124,606 and 834 shares for the nine months ended September 30, 2018 and 2017, respectively.