The S&P Case-Shiller U.S. home price index fell less than expected in the second-quarter as the 20-city composite index posted an annual decline of 15.38%, up from a 14.22% decline in the first quarter.

The Case-Shiller index has fallen every month since peaking in July 2006, but economists say the rate of decline may be slowing, as evidenced by the three-month annualized rates.

Economists were expecting the quarterly index to fall 16.2%.

The three-month annualized rate of decline was 9.01% in the second quarter, compared to the 24.38% decline in the first quarter and a 13.68% drop in the final quarter of last year.

The report said there were continued broad-based declines in the prices of existing single family homes across the U.S., "a trend that prevailed throughout 2007 and has continued through the first half of 2008."

The 10-City and 20-City composite indexes also set new records, with annual declines of 17.0% and 15.9%, respectively. "However, it should be noted that the acceleration in decline was only moderate in June. The May numbers reported annual declines of 16.9% and 15.8%, respectively," the report said.

David Blitzer, chairman of the S&P's index committee, said "While there is no national turnaround in residential real estate prices, it is possible that we are seeing some regions struggling to come back, which has resulted in some moderation in price declines at the national level."

The S&P/Case-Shiller Home Price Indices measures the residential housing market, tracking changes in the value of the residential real estate market in 20 metropolitan regions across the United States.

By Patrick McGee and edited by Stephen Huebl