Vanguard Health Systems Inc., the hospital operator controlled by Blackstone Group LP (BX), raised $450 million in an initial public offering, 22% less than it sought, after pricing the shares below the marketed range. Vanguard sold 25 million shares at $18 each, according to data compiled by Bloomberg, after offering them for $21 to $23. Vanguard will trade on the New York Stock Exchange under the symbol VHS, according to a regulatory filing. The Nashville, TN-based company cut its offering to attract buyers as the Standard & Poor's 500 Index has fallen 3.7% this month amid concern the U.S. economic recovery is stalling. Pandora Media Inc., the streaming radio company, has dropped 16% since its IPO June 14 and LinkedIn Corp., the networking website, is down 29% from its post-IPO high last month.