23 / PRNewswire-FirstCall / -- Select Medical Holdings Corporation ( " Select " ) ( NYSE : SEM ) , the parent of Select Medical Corporation , today announced that it had received notice of the exercise of the underwriters ' over-allotment option to purchase an additional 3,602,700 shares of Select 's common stock at a price per share of $ 10.00 , which is expected to close on October 28 , 2009 , subject to customary closing conditions .