TAMPA - When times were good, Tampa Bay area home sales posted price gains among the sharpest in the nation.

It should be no surprise then, economists say, that the area is now among the nation's top metro areas for falling prices.

The S&P/Case-Shiller home price index, released Tuesday, showed that the Tampa area had the sixth-largest drop in home sales prices in January of 20 metropolitan areas tracked. Tampa had a 15 percent decline in January, compared with the same month the previous year.

Miami, the only other Florida city tracked, tied with Las Vegas for the No. 1 spot. Both posted a 19.3 percent year-over-year decline.

"There's no sign we've hit the bottom yet," said David Blitzer, chairman of the Index Committee for Standard & Poor's.

The numbers are bad news for people who purchased homes near the end of the housing boom in 2005 or 2006. But homeowners who bought before that are faring better, Blitzer said.

For instance, Tampa home prices shot up 138 percent from 2000 to July 2006, he said. The 15 percent drop pales in comparison to that, Blitzer said.

Of the 20 cities tracked, he added, 19 have prices "comfortably above where they were in 2000."

The only exception, he said, is Detroit. The city posted a 15 percent home price drop in January. Current sales prices, Blitzer said, are "within pennies" of what they were in 2000.

Nationwide, the index dropped 10.7 percent from January 2007, after a 9 percent year-over-year decrease through December 2007. The gauge has fallen for 13 consecutive months.

The housing price decline may help to lure buyers back into the beleaguered market, where sellers are struggling under a wave of foreclosures and a tight credit market that has made it more difficult for many Americans to take out mortgages. Inventories have ballooned and purchases have dried up as buyers hold out for prices to fall even further.

Tuesday's report followed a blip of positive news released Monday from state and national Realtors groups.

Sales of previously owned homes edged up last month, according to the National Association of Realtors, ending a six-month streak of declines. In the Tampa Bay area, sales edged up slightly from January to February, but still were 29 percent below January 2007 figures.

The positive sales figure led some analysts to suggest that the housing market is approaching its bottom. But many economists predict that prices will fall for several more months before sales pick up in earnest.

"It's a necessary thing," said Joshua Shapiro, the chief U.S. economist at MFR, a New York economic research firm. "It's like the mess going down in financial markets. You got to get through it. The sooner you get through it you can look for better times."

The majority of the 20 regions included in Tuesday's Case-Shiller survey recorded price declines, with Sun Belt cities such as Las Vegas, Phoenix, and Los Angeles suffering the worst losses in January. Prices in Miami and Las Vegas have lost nearly 20 percent in the 12 months ending in January. Only one region, around Charlotte, N.C., has seen prices rise over the past year.

Only Charlotte, N.C., posted a year-over-year gain. It had a 1.8 percent rise in January compared with a year earlier.

Information from the Associated Press was used in this report. Reporter Shannon Behnken can be reached at sbehnken@tampatrib.com or (813) 259-7804.