Home resales rose to a 1-1/2-year high in January, pushing the supply of properties on the market to the lowest level in almost seven years in a hopeful sign for the housing sector.

The National Association of Realtors said on Wednesday existing home sales increased 4.3 percent to an annual rate of 4.57 million units last month, the fastest pace since May 2010.

It was the latest indication the housing market may be coming off the floor. While economists attributed some of the rise to unseasonably warm winter weather, they also said it signaled genuine improvement.

Sales were up across all four regions of the country, with the West recording the biggest gain -- an 8.8 percent increase.

At least some of the improvement in the last few months could have reflected milder winter weather, but for the most part, it seems that the housing sector may have turned the corner, said Guy Berger, an economist at RBS in Stamford, Connecticut.

The tenor of the report was weakened somewhat by a sharp downward revision to December's sales data to show only a 4.38 million unit sales rate rather than the previously reported 4.61 million unit pace.

A brightening economic outlook, marked by a strengthening labor market and buoyant factories, is giving the housing market some lift. Confidence among homebuilders is near five-year highs and they are breaking more ground on new housing projects.

Residential construction is expected to contribute to growth this year for the first time since 2005.

Robert Toll, executive chairman of luxury homebuilder Toll Brothers, welcomed that progress even as his company announced a surprise quarterly loss on Wednesday.

Since the new home industry is coming off several years of historic low levels of production, we are encouraged by the recent improvement, he said in a statement.

The data did little to lift U.S. stock market sentiment, with shares ending down after weak data on European business activity. Prices for U.S. government debt rose on concerns Greece might not be able to avert a messy default even with a fresh bailout.

The dollar rose against a basket of currencies.

INVENTORY DWINDLING

The U.S. housing market had been held back by an overhang of unsold homes, but steady sales gains are helping to whittle down supply.

The inventory of unsold homes on the market fell 0.4 percent to 2.31 million last month, the lowest since March 2005. That represented a 6.1 months' supply at January's sales pace, the lowest since April 2006 and down from 6.4 months in December.

A supply of six months generally is considered ideal.

While inventories tend to fall in winter and the decline last month could also be reflecting delays in the process of bringing foreclosed properties to the market, there is some real improvement underway.

The homeowner vacancy rate, which is closely correlated to the month supply, fell to 2.3 percent in the fourth quarter of 2011 from 2.4 percent in the prior three months. The rate peaked in 2008.

This vacancy rate is consistent with a glut of about a half a million houses, said Patrick Newport a U.S. economist at IHS Global Insight in Lexington, Massachusetts.

At the current pace, eliminating the overhang should take less than two years, but will probably take longer, because it is concentrated in a few high-unemployment states.

The median home sales price in January fell 2 percent from a year ago to $154,700. That was the lowest since November 2001. Other data on Wednesday showed demand for home purchase loans fell last week, despite mortgage rates holding near historic lows.

The Federal Reserve, which has suggested a number of ways other policymakers could step in to help the beaten-up market, is considering purchasing more mortgage-backed securities to drive mortgages rates even lower.

But some economists are skeptical that would do much good.

I don't think the problem in the mortgage market is high interest rates or availability of liquidity. The problem is lack of jobs and very strict lending standards, said Sung Won Sohn, an economics professor at California State University Channel Islands.

Distressed properties, foreclosures and short sales, which typically occur at deep discounts, accounted for 35 percent of overall sales last month, up from 32 percent in December.

A third of pending existing home sales contracts were canceled, the NAR said. Investors bought 23 percent of homes in January, with first-time buyers accounting for a third of the transactions.

We expect the spring selling season to show some improvement, but we believe it risks disappointing relative to market expectations, said Michelle Meyer, a senior economist at Bank of America Merrill Lynch in New York.

(Editing by Chizu Nomiyama)