A for sale sign sits outside of a house in Miami Beach, October 22, 2009.REUTERS/Carlos Barria

NEW YORK - U.S. home prices in August rose for the fourth straight month, surpassing forecasts and providing the latest sign that the hard-hit housing market is stabilizing after a three-year slump, according a report on Tuesday.

The Standard & Poor's/Case-Shiller composite index of home prices in 20 metropolitan areas rose 1.2 percent in August from July, above the estimate of a 0.7 percent rise found in a Reuters poll. The increase, however, was less than the 1.6 percent seen in July, S&P said.

The composite index of prices in 10 metropolitan areas gained 1.3 percent in August after a 1.7 percent rise the previous month.

The monthly price increases helped the annual rates, with the yearly pace of declines in home prices slowing to a 10.6 percent drop in the 10-city index and a 11.3 percent decrease in the 20-city index.

(Reporting by Julie Haviv, Editing by Chizu Nomiyama)