NEW YORK (CNNMoney.com) -- Stocks slipped Monday afternoon as investors welcomed the White House's pledge to aid subprime mortgage holders, but continued to bail out of housing and financial stocks on worries about the economy.

GM (Charts, Fortune 500) shares fell 4 percent after the automaker reported a drop in November sales versus forecasts for a rise, while other auto sales were mixed.

The Dow Jones industrial average (Charts) lost 0.3 percent with around 2 hours left in the session. The broader S&P 500 (Charts) index lost 0.5 percent. The tech-fueled Nasdaq (Charts) composite lost 0.5 percent.

Treasury Secretary Henry Paulson, speaking at the National Housing Forum Monday, said the United States is aggressively pursuing relief for struggling subprime mortgage holders. Paulson outlined steps the government is taking to help troubled homeowners, but didn't provide more details on plans for freezing interest rates at the lower levels.

The comments seemed to help settle stocks after morning declines, but investors showed reluctance to push stocks much higher on the first trading day of December.

Stocks gained last week after comments from Federal Reserve officials suggested the central bank will cut rates again at its policy-meeting on Dec. 11. But the gains occurred at the end of an unusually rough November on Wall Street in which stocks got slammed on worries that the housing and credit market crisis will push the economy into recession.

Boston Fed president Eric Rosengren said U.S. economic growth will be well below its long-term rate over the next two quarters, according to news reports. Rosengren is a voting member of the Fed's 2007 policy committee. Investors are hoping that Federal Reserve officials, meeting next week, will cut a key short-term interest rate by at least a quarter-point, if not a half-point, so as to speed up the flow of money through the economy.

In economic news, the Institute For Supply Management's manufacturing index for November eased to 50.8 in the month, the group reported, versus forecasts for a slip to 50.5. The index stood at 50.9 in October. Any reading over 50 signifies economic expansion.

Reports are due later in the week on factory orders, consumer sentiment and the big monthly jobs report.

In another sign of the problems in the housing sector, home builder Lennar has unloaded 11,000 properties for 40 percent of their value, selling them to a joint venture it set up with the real estate arm of Morgan Stanley. Shares of both Lennar (Charts, Fortune 500) and Morgan Stanley (Charts, Fortune 500) slipped in the morning.

On the deal front, Vivendi said Sunday that it plans to buy a big stake in Activision and combine it with Vivendi Games to create a rival company to current leader Electronic Arts (Charts). Shares of video game maker Activision (Charts) rallied 17 percent Monday on the news.

Warren Buffett's Berkshire Hathaway (Charts) reportedly bought $2 billion in bonds at the end of last week, issued by power company TXU.

E*Trade Financial (Charts) slumped 10 percent after Banc of America Securities downgraded the company to "sell" from "neutral" and cut its price target, Briefing.com reported.

Dell (Charts, Fortune 500) shares slid for a second session after the company's quarterly earnings report disappointed investors.

Research in Motion (Charts) shares tumbled after a Morgan Keegan analyst downgraded the Blackberry Maker's stock to "market perform" from "outperform."

Market breadth was negative. On the New York Stock Exchange, losers beat winners by a narrow margin on volume of 580 million shares. On the Nasdaq, decliners beat advancers by a similar margin on volume of 940 million shares.

Treasury prices rose, lowering the yield on the 10-year note to 3.90 percent from 3.94 percent late Friday. Treasury prices and yields move in opposite directions.

In currency trading, the dollar slipped versus the euro and the yen.

U.S. light crude oil for January delivery fell 66 cents to $88.05 a barrel on the New York Mercantile Exchange.

COMEX gold for February delivery rose $4.90 to $794 an ounce.