TAMPA - Tampa Bay area home prices continue to fall, but there are signs they have started to stabilize.

Although prices fell 21 percent in April compared with the same month a year ago, monthly decreases are getting smaller, according to data released Tuesday by Standard & Poor's.

Sales prices fell 0.7 percent from March to April, compared with 2.7 percent from February to March, according to the S&P/Case-Shiller national home price index. In January, the monthly drop was 4.4 percent.

"While one month's data cannot determine if a turnaround has begun, it seems that some stabilization may be appearing in some of the regions," said David Blitzer, chairman of the index committee for Standard & Poor's. "We are entering the seasonally strong period in the housing market, so it will take some time to determine if a recovery is really there."

Nationally, sales prices fell 18.1 percent in April compared with the same month last year.

Phoenix, Las Vegas and San Francisco posted the largest drops, at 35 percent, 32 percent and 28 percent, respectively.

Miami, the only other Florida city tracked, posted a 27 percent yearly decline.

The index does not include the actual prices, but recent figures from the Florida Association of Realtors show the median sales price of homes in the Tampa-St. Petersburg-Clearwater area was $141,100 in May. That's down 20 percent from $176,100 in May 2008.

Reporter Shannon Behnken can be reached at (813) 259-7804.