Single-family home prices rose for the first time in 10 months, in an encouraging sign the battered sector is starting to stabilize, a closely watched survey said on Tuesday.

The S&P/Case Shiller composite index of 20 metropolitan areas gained 0.2 percent in February on a seasonally adjusted basis, matching economists' forecasts.

It was the first time prices have gained since April 2011. That gain was itself an anomaly in a string of declines stretching back to May 2010.

But on a non-seasonally adjusted basis, the 20-city index was down 0.8 percent at 134.20, the lowest since October 2002.

David Blitzer, chairman of the index committee at Standard & Poor's, cautioned that while there were some pieces of good news in the report, some areas still continued to decline.

Stock index futures slightly extended declines immediately after the data, with investors also focused on Europe's debt crisis.

Looking forward, we think homes sales will continue to trend upward, which ultimately will result in a slower rate of home value depreciation, said Stan Humphries, chief economist at Zillow.

But any housing recovery will be dependent on job growth. Continued progress in this area is essential to keeping the housing recovery, such as it is, on track.

Seven of the cities saw prices drop on a seasonally adjusted basis, while prices in two cities were unchanged. On an unadjusted basis, 16 of the areas slumped further.

Prices in the 20 cities fell 3.5 percent year over year, moderating from the previous month's decline of 3.8 percent.

(Reporting By Leah Schnurr; Editing by Chizu Nomiyama)