U.S. Stocks Fall, S&P 500 Drops to 12-Year Low; Citigroup Sinks

U.S. stocks slid, sending the Standard & Poor’s 500 Index to a 12-year low, as the government cut shareholders’ stake in Citigroup Inc. by 74 percent and the economy shrank at a faster pace than previously estimated.

Citigroup plunged 39 percent after the Treasury agreed to convert as much as $25 billion of preferred shares into common stock in a third rescue attempt. Bank of America Corp. tumbled 26 percent, snapping a four-day rally in an S&P 500 group of banks. Alcoa Inc. and Boeing Co. fell more than 3.8 percent after the Commerce Department said gross domestic product contracted at a