The National Association of Realtors said that sales of existing homes rose by 2.9 percent in February to a seasonally adjusted annual rate of 5.03 million units. It was the biggest increase in a year and caught economists by surprise. They had been expecting a small decline.

The trade group reported that the median existing sales price in February fell to $195,900. That was the largest year-over-year drop on records that go back to 1999.

Lawrence Yun, chief economist for the Realtors, said that prices in some formerly hot markets in California and Florida were seeing significant price declines now as sellers try to attract buyers.

Analysts cautioned against reading too much into the one-month rise in sales. Many economists are predicting that the steep slump in housing will not bottom-out until later this year after prices fall further and allow huge levels of unsold inventories to be reduced.

"We're not expecting a notable gain in existing-home sales until the second half of this year, but the (February) improvement is nother sign that the market is stabilizing," Yun said.

By region of the country, sales surged by 11.3 percent in the Northeast and were up 2.5 percent in the Midwest and 2.1 percent in the South. The only region of the country to see a decline in the sales was the West, where they dropped by 1.1 percent.

An economist and a Philadelphia-area real estate agent said that mortgage rates and realistic pricing by sellers of existing homes could explain the bounce in February sales in the Northeast.

Brian Bethune, U.S. chief financial economist for Global Insight Inc., agreed that the February numbers could be a signal that the decline in existing home prices and sales will bottom out in the first quarter. The Philadelphia region's diversified industrial base and strength in pharmaceuticals and health care are helping it weather the current downturn, especially compared with the New York area, which is taking a greater hit because of the deep losses in the financial sector.

"Overall, the lower mortgage rates were a factor and that comes into play in the Northeast, where the average [home] price tends to be a little higher," Bethune said. "That's the only factor I could come up with to explain the Northeast. The economic base in the Northeast is relatively solid."

David Oser, an agent with Re/Max in Bryn Mawr, said that home prices in the areas of Delaware and Montgomery counties where he works are at about 2005 levels, but the region "didn't get the kind of bloom they had in Las Vegas, or Orlando or California. We didn't get the boom and we didn't get the bust."

Oser said he's sold houses recently on the Main Line, Collegeville and Lansdowne. "I'm finding some sellers are not realistic but others are," he said. "Homes that are in good shape and are priced properly are selling fine. I'm having a very good year."

Sales of existing homes fell by 12.7 percent in 2007, the biggest decline in 25 years. Over the past two years, housing has been in a steep downturn made worse by a severe credit crunch as financial institutions tightened their lending standards in reaction to their multibillion-dollar losses on mortgages that have gone into default.

The steep slump in housing has raised concerns about a possible recession. Democrats are pushing the Bush administration to do more to stem a tidal wave of mortgage foreclosures to keep more unsold homes from being dumped on an already glutted market.

Sen. Hillary Clinton, campaigning for the Democratic presidential nomination, today called on President Bush to appoint an emergency working group on foreclosures to recommend new ways to confront the housing crisis.

"Over the past week, we've seen unprecedented action to maintain confidence in our credit markets and head off a crisis for Wall Street banks," Clinton said. "It's now time for equally aggressive action to help families avoid foreclosure and keep communities across this country from spiraling into recession."