This excerpt taken from the PNC 10-K filed Mar 2, 2009.
National City Warrants
As part of the National City transaction, warrants issued by National City converted into warrants to purchase PNC common stock. The holder has the option to exercise 28,022 warrants, on a daily basis, commencing June 15, 2011 and ending on July 15, 2011, and 28,023 warrants, on a daily basis, commencing July 18, 2011 and ending on October 20, 2011. The strike price of these warrants is $750 per share. Upon exercise, PNC will deliver common shares with a market value equal to the number of warrants exercised multiplied by the excess of the market price of PNC common stock over the strike price. The maximum number of shares that could be required to be issued is approximately 5.0 million, subject to adjustment in the case of certain events, make-whole fundamental changes or early termination. PNC has reserved 5.0 million shares for issuance pursuant to the warrants and 3.6 million shares for issuance pursuant to the related convertible senior notes.