NEW YORK (AP) - Wall Street turned cautious yesterday after a two-day rally and as downbeat corporate news reminded investors that the economy's troubles will not soon ease. Stocks tumbled while demand for the safety of government debt spiked.

The Dow Jones industrials fell 242 points, while broader indexes showed more moderate declines. Wall Street's uneven pull-back illustrated the fragmented nature of the markets. Some investors snapped up hard-hit technology names, while a bleak forecast from FedEx Corp. made others fearful of stocks.

Demand for ultra-safe Treasury bills spiked so high that investors were willing to earn no interest on their investments at a Treasury Department auction. Interest rates on four-week Treasury bills slid to zero from 0.04 percent a week earlier in a Treasury Department auction yesterday.

"Investors truly don't want to buy into this market, they are willing to lose money safely like in Treasurys," said Chris Johnson, manager of quantitative analysis at Schaeffer's Investment Research in Cincinnati.

Investors are also worried that companies' difficulties could make an economic turnaround difficult. FedEx Corp. cut its forecast for fiscal 2009 earnings and capital spending late on Monday as the slumping economy eroded package deliveries.

The stock market's retreat was not a surprise given the steep advance of the past two sessions. But the reasons for the selling were not simply based on two days of gains, analysts said. Wall Street is still trying to determine how badly companies' woes will dent profits and how soon President-elect Barack Obama's plan to introduce a flood of public works spending could aid the economy.

"The markets are just expressing a tremendous amount of ambivalence about the future," said Marian Kessler, co-portfolio manager of the Becker Value Equity Fund in Portland, Ore. "The market is grappling with what is certainly going to be a fairly deep recession in 2009."

That caution means like volatility is likely to continue, observers said.

According to preliminary calculations, the Dow Jones industrial average fell 242.85, or 2.72 percent, to 8,691.33.

Broader stock indicators also declined. The Standard & Poor's 500 index fell 21.03, or 2.31 percent, to 888.67. The Nasdaq composite index fell 24.4, or 1.55 percent, to 1,547.34.

The Russell 2000 index of smaller companies fell 15.67, or 3.26 percent, to 465.71.

Declining outnumbered advancers by more than two-to-one on the New York Stock Exchange, where volume came to 1.44 billion shares.

Bond prices rose after the Treasury auction and as stocks fell. The yield on the benchmark 10-year Treasury note, which moves opposite its price, fell to 2.65 percent from 2.74 percent late Monday. The yield on the three-month T-bill, considered one of the safest investments, rose to 0.03 percent, from 0.01 percent late on Monday. Still, the low yields indicate a high degree of investor unease.

The dollar rose against most other major currencies, while gold prices slipped.

Oil prices fell even amid investor expectations that OPEC will announce a big production cut next week to curb crude's stunning 70 percent-free-fall over the past five months. Light, sweet crude fell $1.64 to settle at $42.07 a barrel on the New York Mercantile Exchange.

Investors' anxiety about the struggling economy has recently been accompanied by some hopes that market might be carving a bottom. On Friday and Monday, the Dow logged a two-day rally of 560 points.

Those gains came as the market tried to look at how the economy might be faring next year. Typically, Wall Street looks six to nine months ahead.

"The economic news still stinks...but what's going on is that people are no longer looking at the present. They're looking at the future," said Alfred Goldman, chief market strategist at Wachovia Securities in St. Louis.

"They're beginning to assess that all the dramatic fiscal and monetary stimulus already on the table and more to come will turn this economic around maybe next summer."

Still, when it comes to a potential stock market rebound, "it's not going to be a one-way trip," Mr. Goldman said. "We still have a tonne of dismal news, and so much technical and emotional damage done, that investor confidence is going to come back slowly, not quickly."