NEW YORK » Wall Street snapped back yesterday after its biggest selloff in years amid growing expectations that lawmakers will salvage a $700 billion rescue plan for the financial sector. But the seized-up credit markets where businesses turn to raise money showed no sign of relief.

One day after the biggest point drop in its history, the Dow Jones industrial average rose 485 points, or more than 4.5 percent - the latest in a string of extraordinarily volatile days in the stock market. It was third-biggest point gain in the Dow's history and the biggest percentage climb in the Dow in six years.

The recovery in stocks wasn't unexpected as carnage on Wall Street often attracts bargain hunters, though questions remain about how investors will proceed. Without a bailout plan in place to absorb soured mortgage debt and other bad loans from battered banks, investors are left wondering what might restore confidence in lending.

Major stock indexes were almost a sideshow during the session, with the credit markets as the main event. A key rate that banks charge to lend to one another shot higher, a tightening of the availability of credit that could cascade through the economy.

Traders on the floor of the New York Stock Exchange, still stunned from Monday's 777.68-point rout in the Dow, warned that the government needs to approve a plan that will sweep away the fears that hobbled the credit markets. While U.S. political leaders have vowed to revisit the issue, the House isn't slated to meet again until tomorrow. The Senate plans to vote on the financial plan tonight.

“;If it doesn't pass, then look out below,”; said Jason Weisberg, an NYSE trader for Seaport Securities. “;It could get ugly.”;

The Dow rose 485.21, or 4.68 percent, to 10,850.66 after falling nearly 7 percent on Monday to its lowest close in nearly three years. It was the largest point drop and 17th largest percentage drop in the blue-chip index. The percentage decline was far less severe than the 20-plus-percent drops seen in the stock market crash of October 1987 and before the Great Depression.

Broader stock indicators also bounced higher. The Standard & Poor's 500 index recovered 58.35, or 5.27 percent, to 1,164.74, and the Nasdaq composite index rose 98.60, or 4.97 percent, to 2,082.33.

The S&P fell 8.79 percent Monday, while the Nasdaq lost 9.14 percent.

Advancing issues beat decliners by about 2 to 1 on the New York Stock Exchange, where volume came to 5.84 billion shares.

The Russell 2000 index of smaller companies rose 21.86, or 3.32 percent, to 679.58.

The yield on the 3-month Treasury bill rose yesterday to 0.89 percent from 0.14 percent late Monday. The yield fell Monday as investors clamored for the safety of government debt. The yield on the benchmark 10-year Treasury note, which moves opposite its price, rose to 3.83 percent from 3.58 percent late Monday. The dollar rose against other major currencies and gold prices advanced.

Light, sweet crude rose $4.27 to settle at $100.64 on the New York Mercantile Exchange.

Though the blue-chip index rose sharply yesterday, the main worry for traders is that a lack of a plan will make it nearly impossible for some companies to fund basic operations like making payroll. Participants in the credit market buy and sell debt that companies use to finance operations.

The benchmark London Interbank Offered Rate, or LIBOR, that banks charge to lend to one another, rose sharply yesterday, making it more expensive and difficult for consumers and businesses to borrow money. In addition, credit card debt and more than half of adjustable-rate mortgages are tied to LIBOR, so an increase isn't welcome for many consumers. LIBOR for 3-month dollar loans rose to 4.05 percent from 3.88 percent on Monday. LIBOR for 3-month euro loans, meanwhile, rose to 5.27 percent, from 5.22 percent Monday.