Single-family home prices fell in June and disappointed expectations, a closely watched survey said on Tuesday.

The S&P/Case Shiller composite index of 20 metropolitan U.S. areas declined 0.2 percent in June on a seasonally adjusted basis. A Reuters poll of economists had forecast a flat reading.

Non-seasonally adjusted prices rose 1.0 percent in the 20 cities, in line with expectations.

"Home price gains continue to ease as they have since last fall," David Blitzer, chairman of the index committee at S&P Dow Jones Indices, said in a statement.

"For the first time since February 2008, all cities showed lower annual rates than the previous month. Other housing indicators, starts, existing home sales and builders' sentiment, are positive. Taken together, these point to a more normal housing sector."

Prices in the 20 cities rose 8.1 percent year over year, shy of expectations for 8.4 percent.

A broader measure of national housing market activity that Case-Shiller is now releasing on a monthly basis rose at a slower pace year over year, coming in at 6.2 percent. Previously, Case-Shiller had released its national index on a quarterly basis.

The seasonally adjusted 10-city gauge fell 0.1 percent in June versus a 0.2 percent decline in May, while the non-adjusted 10-city index rose 1.0 percent in June compared to a 1.1 percent rise in May.

Year over year, the 10-city gauge also rose 8.1 percent.