Home prices are falling faster in the largest U.S. cities, and a record number of foreclosures are expected to push prices down further through next year.

The Standard & Poor's/Case-Shiller 20-city home price index released Tuesday fell 0.7 percent in September from August. Eighteen of the cities recorded monthly price declines.

Cleveland recorded the largest decline. Prices there dropped 3 percent from a month earlier. Prices in San Francisco, Los Angeles and San Diego, which had been showing strength this year, also dropped in September from August.

Washington and Las Vegas were the only metro areas to post gains in monthly prices.

The 20-city index has risen 5.9 percent from their April 2009 bottom. But it remains nearly 28.6 percent below its July 2006 peak.

And home prices have fallen in 15 of the 20 cities in the past year.

Prices rose in many cities from April through July, mostly boosted by government tax credits which have since expired. Job worries and record high foreclosures are dampening buyer demand and weighing on prices.

The national quarterly index, which measures home prices in the nine U.S. census regions, dropped 2 percent in the third quarter from the previous quarter.