TAMPA - Federal tax incentives fueled an increase in the nation's home prices in May, but the Bay area saw a slight decrease compared to last year.

Prices in the Tampa-St. Petersburg-Clearwater metro area fell 1.5 percent from the same time a year ago, according to Standard & Poor's/Case-Shiller price index, released today.

On a monthly basis, local prices were stagnant, rising 0.9 percent from April, following a 0.5 percent increase from March to April.

Nationally, home prices rose in May for the second straight month as federal tax incentives pulled more buyers into the market.

The index, which tracks prices in 20 markets, posted a 1.3 percent monthly increase in May and a 4.6 increase from a year ago.

"While May's report on its own looks somewhat positive, a broader look at home price levels over the past year still do not indicate that the housing market is in any form of sustained recovery," said David M. Blitzer, chairman of the index committee.

Nineteen of 20 cities showed price gains month over month. Minneapolis and Atlanta led the way with 2.8 percent and 2 percent increases, respectively. And San Diego posted its 13th straight monthly gain.

Only Las Vegas recorded a price decline. The metro hit a new record low in May. Home prices there have lost 56.4 percent of their value since peaking in August 2006.

And while Detroit recorded a 0.7 percent increase from April, the average home price there is about same as it was in 1994.

Miami, the only other Florida city tracked saw May prices increase 1.2 percent from last year and 0.9 percent from April.

While some of the increase is attributed to home buyers taking advantage of tax credits, May is typically a strong month for real estate.

The economy continues to be lackluster and foreclosures are still rising in states such as Florida. The Sunshine state and Tampa Bay are among the hardest-hit by foreclosures.

Many economists and real estate professionals don't expect the price gains to last. Some think prices will remain flat for the rest of the year, while others think prices will begin to fall again.

Foreclosures are expected to increase this year, and that would further push down prices.

IHS Global Insight economist Patrick Newport said he predicts prices will fall another 6 percent to 8 percent before turning around next year.

Information from The Associated Press was used in this report. Reporter Shannon Behnken can be reached at (813) 259-7804.