17. Capital Stock

Nonvoting Participating Preferred Stock. The Company’s preferred shares authorized, issued and outstanding consisted of the following:

	March 31,		December 31,
	2018		2017
Series A
Shares authorized, $0.01 par value		20,000,000		20,000,000
Shares issued and outstanding		—		—
Series B
Shares authorized, $0.01 par value		150,000,000		150,000,000
Shares issued and outstanding⁽¹⁾		823,188		823,188
Series C
Shares authorized, $0.01 par value		6,000,000		6,000,000
Shares issued and outstanding⁽¹⁾		143,458		246,522
Series D
Shares authorized, $0.01 par value		20,000,000		20,000,000
Shares issued and outstanding		—		—

⁽¹⁾	Shares held by PNC.

Share Repurchases. The Company repurchased 0.6 million common shares in open market transactions under the share repurchase program for approximately $335 million during the three months ended March 31, 2018. At March 31, 2018, there were 5.8 million shares still authorized to be repurchased.

PNC Capital Contribution. During the three months ended March 31, 2018, PNC surrendered to BlackRock 103,064 shares of BlackRock Series C Preferred to fund certain LTIP awards.