New York ? An upbeat outlook from General Motors and a ratings upgrade of Sun Microsystems gave Wall Street a burst of enthusiasm Monday, propelling stock prices sharply higher.

A strong housing report also contributed to investors’ buoyant mood and helped the Dow industrials surge more than 170 points to their strongest close in six weeks.

But analysts remained wary about the market’s ability in the near term to hold onto gains, given last week’s fluctuations and ongoing fears about earnings and accounting practices. Buyers have been enticed by cheaper prices following the market’s yearlong decline rather than a belief that business is poised for improvement.

The Dow soared 177.56, or 1.8 percent, to close at 10,145.71. It was the Dow’s strongest close since Jan. 8, when it finished at 10,150.55.

The Dow’s recent sessions have proved choppy as the blue chip index alternated between triple-digit gains and losses all last week. The Dow rose 133.47 Friday.

General Motors rose $2.37 to $55.48 after raising its first-quarter and 2002 earnings estimates. GM, which cited better-than-expected sales in the United States, also said it was increasing planned production.

Other automakers benefited from GM’s news. DaimlerChrysler climbed $1.85 to $39.73.

While economic reports have indicated that business is strengthening, the timing of an economic turnaround remains uncertain and investors are looking to company earnings outlooks for indicators that business is improving.

Blue-chip gains were widespread. Citigroup rose $1.39 to $43.79, while Wal-Mart gained 70 cents to $60.65. Both are Dow industrials.

“Remember the Dow is just 30 stocks, but it is acting very well,” said Gary Kaltbaum, market technician for Investors’ Edge Partners. “The Nasdaq is still wavering big time. We are still in a major bear market for technology.”

Technology, which has suffered most of this year’s selling, was lifted by Sun Microsystems. Sun advanced 80 cents to $8.87 after Banc of America raised its rating to “buy” from “market perform,” citing an attractive stock price and solid prospects for growth in the second half of 2002.

Other tech winners included wireless provider Qualcomm, climbing $3.21 to $35.91 after reaffirming its forecast for the fiscal second quarter. Citrix Systems rose $1.26 to $14.76 on an upgrade from UBS Warburg to “strong buy” from “buy.”