June 25 (Bloomberg) -- Home prices throughout California and in the Las Vegas area fell from a year earlier in May as a glut of foreclosed property pushed down the value of single- family houses and condominiums.

The median price for an existing, single-family detached house in California declined 30 percent to $267,570, the California Association of Realtors said today in a statement. In the Las Vegas area, the median price for houses and condominiums fell 44 percent to $135,000, San Diego-based MDA DataQuick said in a separate statement today.

About 73 percent of all existing houses and condos sold in the Las Vegas-Paradise area were foreclosures last month, up from 56 percent a year earlier, and such sales accounted for 51 percent all existing-home transactions in California, MDA DataQuick said. Foreclosure sales represented 40 percent of California resales a year ago, the research company said.

“In California and the West and, really, a lot of the country, we have to be ready for more waves of foreclosures coming through for at least the next year,” Andrew LePage, an analyst with MDA DataQuick, said in an interview. “And no one really knows how big those waves are going to be.”

California is on target for 556,590 home sales this year, based on May’s pace of transactions, the state’s Realtors association said. That’s up from a 411,770 pace in May 2008. May’s sales were up 2.9 percent from April.

Inventory Shrinks

The median number of days it took to sell a California house was 53.5 in May, up from 49.2 days a year earlier, the association said. The group’s unsold inventory index for existing, single-family homes was 4.2 months in May, down from 8.7 months a year earlier. The index shows the time needed to deplete the supply of homes on the market at the current sales rate.

May was the third consecutive month that the median price for California single-family homes rose from the previous month. The May median was up 4.2 percent from April, according to the Realtors group.

“Nearly all regions in the state reported positive month- to-month changes in median price,” Leslie Appleton-Young, chief economist with the California Association of Realtors, said in the group’s statement.

The median condominium price in California dropped 34 percent from a year earlier to $236,660, the Realtors association said. The median was up 5 percent from April. The number of condos sold rose 35 percent from a year earlier and 5.2 percent from April.

In the Las Vegas area, the median price has dropped on a year-over-year basis for 25 consecutive months, MDA DataQuick said. May’s median was 57 percent below the November 2006 peak of $312,000, the research company said.

MDA DataQuick, a unit of Richmond, British Columbia-based MacDonald, Dettwiler and Associates Ltd., compiles surveys using county records and supplies real estate information to customers including public agencies, lenders and title companies.

To contact the reporter on this story: Daniel Taub in Los Angeles at dtaub@bloomberg.net.

Last Updated: June 25, 2009 15:59 EDT