The U.S. housing market is showing signs of stabilization, according to inventory data released on Monday by national real estate brokerage ZipRealty.

Emeryville, California-based ZipRealty reported a drop in the number of Multiple Listing Service-listed homes for the 12th consecutive month in June.

The number of single-family homes and condos listed for sale decreased in June from May by 2.1 percent, bringing the total number of active listings in 28 major U.S. markets to 696,858, the company said.

Additionally, ZipRealty tracked an increase in the median list price in the 28 markets to $270,440 in June from $270,027 in May. Despite the sequential increase the median list price still decreased 2.72 percent when compared to June 2008.

ZipRealty's Housing Inventory Index, compiled from local MLS data, for June showed that Las Vegas, Los Angeles and Phoenix all recorded a decline in inventory, which the company said may have contributed to some homes receiving several multiple bids.

Las Vegas, Phoenix, San Francisco Bay Area and Los Angeles showed median list prices flatten or increase. California showed the most dramatic inventory declines, with Los Angeles showing a 53.9 percent decrease year-over-year while Bakersfield/Fresno tracked a 56.2 percent decrease.

'Affordability' has been the buzz word in real estate this summer, and with a significant number of listed homes bank-owned we're seeing instances in some areas of banks dropping prices to generate more offers from buyers, ZipRealty President and CEO Patrick Lashinsky, said in a statement.

If the number of home listings continue declining and buyer interest and activity remains strong, we should see sales prices and home values increase as we head into the fall, he said.

(Editing by Theodore d'Afflisio)