Los Angeles County housing prices declined 4 percent in January, and they don’t look like they are going to improve any time soon.

The median price of new and existing homes fell to $330,000, the lowest it has been since last February, before federal home tax credits temporarily goosed the market in the spring, according to HomeData of Hicksville, N.Y.

It’s also the average price of summer 2009, a few months into what then appeared be the start of a recovery, which later petered out. Further evidence of a weak market: The number of homes sold fell to 3,344 units in January, 10 percent off a year earlier.

Gary Painter, director of research at the USC Lusk Center for Real Estate, said that home sellers shouldn’t expect any good news in the first quarter.

“I would expect to see declines in the next three months,” said Painter, who believes a growing number of foreclosed and short-sale houses will continue to depress the local market.

There is plenty of evidence to support the analysis. In December, new-housing starts nationwide fell to a 14-month low as discounted existing homes continued to hit the market.

Lawrence Yun, chief economist at the National Association of Realtors, believes the number of delinquent mortgage grew steadily in the second half of 2010.

“That trend will likely result in an increase in the prime foreclosure rate down the road,” he wrote in a recent report.

Locally, home prices were all over the map. Median prices rose in wealthy neighborhoods such as Beverly Hills’ famous 90210 ZIP code and Pasadena’s 91105, but were off in Santa Monica’s 90402 and in Palos Verdes Estates.

Painter said he doesn’t believe the market will show any broad recovery for 12 to 18 more months despite signs the economy is slowly healing.

“There’s a huge inventory of houses, and it’s going to take time to work through this backlog,” he said. “Certainly the increase in consumer spending is positive, but consumers are going to wait to get back into housing until they see a definite turnaround.”