WASHINGTON (MarketWatch) -- Resales of U.S. single-family homes and condos fell 2.6% in June to a seasonally adjusted annual rate of 4.86 million, the lowest level in 10 years, the National Association of Realtors reported Thursday.

Resales have sunk 15.5% in the past year and are down about 33% from the peak in 2005. The pace of sales has been relatively stable since last August at around a 5 million annual pace. Read the full release.

Economists surveyed by MarketWatch expected sales to fall to 4.95 million. See Economic Calendar.

The median sales price fell 6.l% in the past year to $215,100.

The inventory of unsold homes on the market rose 0.2% to 4.49 million, an 11.1-month supply at the current sales pace, the second-highest inventory level since the mid-1980s.

In a separate report, the Census Bureau said about 6.1 million housing units are vacant and available either to rent or buy. About 10% of the homes built for sale in this decade are vacant, while more than 25% of rental units built in this decade are vacant, the report said.

"We are faced with a considerable excess of housing units that is only likely to worsen over coming quarters, and for which there is no quick solution," wrote Richard Moody, chief economist for Mission Residential.

In the Realtors report, sales of single-family homes fell 3.2% to a seasonally adjusted annual rate of 4.27 million, the lowest since January 1998. Sales of condos rose 1.7% to an annual rate of 590,000, the highest since November.

About a third of sales are distressed sales, either foreclosures or short sales, in which homeowners accept less than they owe on the house, with the lender taking the loss. Many foreclosures aren't included in the data at all because they are not sold through the Realtors' multiple-listing service.

On Wednesday, the House approved sweeping legislation designed to help the housing market, including back-stop support for Fannie Mae and Freddie Mac, help for homeowners to refinance high-rate loans, and a $7,500 tax credit for first-time home buyers. See full story.

The legislation could help the housing market to recover, said Lawrence Yun, chief economist for the real estate trade group. About 3 million home buyers could take advantage of the tax credit for first-time home buyers before it expires next July, he said.

Resales fell 6.6% in the Northeast, fell 3.4% in the Midwest, fell 3.1% in the South and rose 1% in the West. Sales are increasing in areas that have seen the largest declines in prices, Yun said, including Riverside and Sacramento, Calif., Orlando, Fla., and Phoenix, Ariz.

Sales are dropping in once-healthy areas, such as Atlanta, Ga., Dallas, Texas, and Charlotte, N.C.

In a separate report, the Census Bureau said the homeownership rate rose in the second quarter to 68.1%, not statistically different from the 67.8% in the first quarter.

The vacancy rate for rental and owner-occupied units declined in the second quarter, but was not statistically different from the first quarter.

Of 40 million rental units, 10% are vacant, down from 10.1% in the first quarter and up from 9.5% a year ago. For the 78 million units typically occupied by owners, the vacancy rate fell from a record 2.9% in the first quarter to 2.8% in the second quarter.

Three years ago, the homeowner vacancy rate was 1.8%. About 2.2 million vacant homes are for sale, the government said. While 2.1 million units were added to the housing stock since last year, 1.26 million more units are vacant, the government said.