U.S. single-family home prices rose in May, though the pace of gains cooled compared to the month before, a closely watched survey showed on Tuesday.

The S&P/Case Shiller composite index of 20 metropolitan areas gained 1 percent on a seasonally adjusted basis, shy of economists' forecast for a 1.5 percent increase. That marked a slower pace from April's 1.7 percent rise.

On a non-adjusted basis, prices rose 2.4 percent.

Compared to last May, prices also fell short of expectations, rising 12.2 percent from a year earlier. Still, it was the biggest annual gain since March 2006, matching a record set in April.

The report was unlikely to alter economists' views that the housing sector continues to recover, making it a bright spot for the economy.

All 20 cities rose on a yearly basis, led by a 24.5 percent surge in San Francisco.