The House of Representatives delivered a stunning defeat to legislation designed to rescue the nation's troubled financial system, sweeping aside a call from President Bush to "send a strong signal" of confidence to markets at home and abroad.

The 228-205 vote Monday exposed deep unease among rank-and-file lawmakers in both parties with what would be an unprecedented intervention in the private sector. The vote came as turmoil in financial markets widened, prompting the Federal Reserve to inject new capital into credit markets and forcing the government-arranged sale of Wachovia Corp. to Citigroup. Monday, the Dow Jones Industrial Average plummeted 777.68 points, its biggest one-day drop in history. It ended down 7% at 10365.45, down 9.3% since crisis erupted a few weeks ago on Wall Street following the meltdown of Lehman Brothers Holdings. All 30 of the blue-chip indicator's components fell Monday.

The Bush-backed package now faces an uncertain future, though party leaders on both sides of the aisle are sure to consider revising the initiative, which Mr. Bush said Monday is needed to "keep the crisis in our financial system from spreading throughout our economy." After the vote, House Minority Leader John Boehner (R., Ohio) said there would be an effort to bring back another bill, with further changes. "We've got to find a true middle ground," he said. "We need everybody to calm down and relax and get back to work."