Single-family home prices picked up for the third month consecutive month in April, showing signs that the housing market recovery is gaining traction.

The S&P/Case-Shiller composite index of 20 metropolitan areas rose 0.7 percent on a seasonally adjusted basis in April, well above economists' expectations of a 0.4 percent gain. The March data were also revised significantly higher to show a month-on-month gain of 0.73 percent, compared with the 0.09 percent initial estimate.

Only three out of the 20 cities in the index saw declines in April on a seasonally adjusted basis. While a broad regional variation remains, the fact that some of the areas hardest hit during the housing downturn -- such as Florida, Arizona, and California -- have seen gains in recent months is a positive sign that the gradual improvement in housing conditions is becoming somewhat broader based.

We continue to expect national home price indices to rise about 3 percent from the year-ago period in 2012, Michael Gapen, a senior U.S. economist at Barclays Plc in New York, wrote in a note.