Financial markets endured another difficult session Monday ahead of a planned House vote on an unpopular $700 billion plan to rescue troubled financial companies and as investors examined a deal for Wachovia Corp. The Dow Jones industrial average fell nearly 300 points, while demand for safe-haven buying in government debt remained high ahead of the vote.

Wall Street fears the government's plan to buy up toxic debt wouldn't be sufficient to resuscitate nearly frozen credit markets.

Investors also reviewed the buyout at Wachovia. The Federal Deposit Insurance Corp. said Monday Citigroup Inc. will acquire Wachovia's banking operations and that the deal protects Wachovia debtholders — a welcome prospect for investors given the strains in the credit markets. Investors had been worried about Wachovia's stability as it grappled with mounting losses over souring mortgage debt. Citi rose 69 cents, or 3.4 percent, to $20.84.

Investors appeared to find some reassurance in a move by the Federal Reserve and other countries' central banks to pump money into the world's credit markets. The Fed said it would boost the amount of 84-day cash loans available to U.S. banks to $75 billion, up from $25 billion. The plan will triple the supply of 84-day loans to $225 billion from $75 billion.

The news comes as President Bush and congressional leaders looked to shore up support for the rescue measure, which they and many on Wall Street believe is a difficult but necessary step to revive moribund credit markets. Banks and other financial houses are hesitant to lend to one another because of fears about bad mortgage debt on companies' books.

Tight lending conditions make it hard and expensive for businesses and consumers to get loans, which can hurt the economy.