U.S. single-family home prices in May rose from the previous year at the same pace as April but fell short of forecasts, as housing construction slowed and new home sales lagged existing home sales, a closely watched survey said on Tuesday.

The S&P/Case Shiller composite index of 20 metropolitan areas in May gained 4.9 percent year over year, matching the pace set in April. Economists polled by Reuters had projected a stronger pace of a 5.6 percent increase.

Denver, San Francisco, and Dallas experienced the biggest year-over-year home appreciation among the 20 cities with price increases of 10.0 percent, 9.7 percent and 8.4 percent, respectively.

"As home prices continue rising, they are sending more upbeat signals than other housing market indicators,” David Blitzer, chairman of the index committee at S&P Dow Jones Indices, said in a statement.

Blitzer added price increases have settled in a 4-5 percent rate following double-digit rises in 2013.

He blamed first-time homebuyers as "the weak spot" for the price plateau. 

By Richard Leong- Reuters (Editing by Chizu Nomiyama; Editing by Chizu Nomiyama)