The credit markets did show some slight signs of easing as demand for safe-haven investments decreased, though that offered little comfort to investors highly anxious about the extremely low lending levels and their impact on the economy. The markets seized up last month after Lehman Brothers Holdings Inc. filed for bankruptcy and the government stepped in to rescue insurer American International Group Inc.

The Fed's latest move to lubricate the credit markets stops short of a broad interest rate reduction that some investors say is necessary to restore confidence in the market. Other market watchers argue, however, that more focused steps like Fed's decision to buy commercial paper are what's needed.

Investors remain worried about financial companies like Bank of America Corp., which fell after slashing its dividend and reporting that its third-quarter profit fell 68 percent. The stock fell $8.45, or 26 percent, to $23.77 Tuesday. It was by far the steepest decliner among the 30 stocks that comprise the Dow industrials.

And a rumor that Mitsubishi UFJ Financial Group Inc. was pulling out of a deal to acquire up to 24.9 percent of the voting shares of Morgan Stanley sent the investment bank's stock tumbling $5.85, or 25 percent, to $17.65. The companies denied the rumor, but the Street was panicky enough that it still sent Morgan Stanley and other financials tumbling.

Investors are fearful that financial companies will continue to face cash shortages even with efforts in Washington and by other governments to resuscitate lending.

"It's such a widespread loss of confidence and, to some extent, a race for the exits," Johnson said.

Stocks ended lower for the fifth straight session. The Dow fell 508.39, or 5.11 percent, to 9,447.11. The drop came a day after the blue chips fell below 10,000 for the first time in four years. The Dow skidded as much as 800 points on Monday before finishing with a loss of 370.

Broader indexes also fell. The S&P 500 index declined 60.66, or 5.74 percent, to 996.23, the first close below the 1,000 mark since September 2003. The Nasdaq composite index fell 108.08, or 5.80 percent, to 1,754.88.

The dollar was mostly lower against other major currencies, while gold prices rose.

Oil prices rebounded after plunging Monday to an eight-month low on concerns a global recession will undermine demand for crude. Light, sweet crude rose $2.25 to settle at $90.06 a barrel on the New York Mercantile Exchange.