U.S. Stocks Decline on Mortgage Concern; Bear Stearns Falls

June 22 (Bloomberg) -- U.S. stocks plunged, capping the Dow Jones Industrial Average's worst week since early March, as concern intensified banks will be saddled with losses on mortgage bonds. --- Banks and brokerages contributed 28 percent to the drop in the Standard & Poor's 500 Index, led by Citigroup Inc., Bank of America Corp. and JPMorgan Chase & Co. Exxon Mobil Corp. fell the most in the Dow average after the price of natural gas slid to a three-month low.