The rate of vacancies for homes slipped slightly in the second quarter, a government report showed on Tuesday, but it was not enough to promise improvement in the hard-hit housing market.

The homeowner vacancy rate eased to 2.5 percent from 2.6 percent in the January-March period, the Commerce Department said. Compared with the second quarter of 2009, the rate was unchanged.

The homeowner vacancy rate is the proportion of the homeowner inventory that is vacant for sale.

Rental housing vacancies were unchanged from the first quarter at 10.6 percent. Rental vacancies peaked at 11.1 percent in the third quarter of 2009.

An excess supply of homes is holding back the housing market's recovery from a three-year slump and casting a shadow over the health of the broader economy as it digs out of its worst downturn since the 1930s.

The decline in housing starts has been large enough to lead to a downtrend in inventories, but inventories of existing homes will not begin to come down appreciably until the foreclosure wave nears an end, wrote economists at Moody's Analytics in West Chester, Pennsylvania.

That suggests the oversupply of homes will continue to put downward pressure on prices until this time next year, at the earliest.

The homeownership rate, which is the proportion of households that are owner-occupied, fell to 66.9 percent from 67.1 percent in the first quarter. It was the lowest in more than 10 years.

Given the magnitude of the housing crash and the residual strains on credit, it could be a long time before homeownership rates rise again, the Moody's Analytics economists said.

(Reporting by Lucia Mutikani; Editing by Dan Grebler)