TAMPA - During the housing boom, prices in Miami and Tampa more than doubled, spurring builders and speculators to flock to the areas. Now, the two cities lead the nation in home price declines, and economists predict prices will continue falling through much of the new year.

In October, Miami and Tampa posted yearlong home price declines of 12.4 percent and 11.8 percent, respectively, according to Standard & Poor's/Case-Shiller home price index, released Wednesday.

Those were the largest drops among 20 cities tracked by the index and were nearly double the national average of 6.1 percent. It was the 10th consecutive month the index showed price declines in Tampa.

"After 15 years of growth, the Florida markets are in a large downturn right now," said Maureen Maitland, a vice president with S&P. "This is a reality check. Like stocks and bonds, home prices can't go up forever."

Even though home prices are falling, Maitland points out that Tampa homes are still selling for 106 percent more than they did in January 2000, so the earlier people bought, the more appreciation they're seeing. That's little consolation, though, for some sellers who bought toward the end of the boom and are now finding their homes valued less than they paid for them.

"Unfortunately for sellers, prices could drop another 5 to 10 percent, and there is a real need for sellers to get aggressive with pricing," said Mike Larson of Weiss Research in Jupiter.

The index tracks individual homes through repeat sales and takes a weighted average of the sales price differences for those homes. Some economists think the index more accurately reflects price trends than median prices reported by the national and state associations of Realtors.

The index does not include actual home prices, though. The Florida Association of Realtors is expected to release November sales data next week. The association's October data show that the median sales price of homes in the Tampa-St. Petersburg-Clearwater area was $209,000, down 7 percent from the same month last year.

Tampa and Miami are not alone. The S&P/Case-Shiller index painted a bleak picture of prices in other parts of the nation.

Nationally, home prices fell for the 10th consecutive month. Besides the Florida cities, Detroit, San Diego, Phoenix and Las Vegas also posted double-digit declines.

Among the 20 metropolitan areas, 11 posted record monthly declines. Tampa did not, but missed that distinction by only a tenth of a percent, Maitland said. August showed a slightly higher drop, she said.

Atlanta and Dallas, which had previously been posting price appreciation, fell in October compared with a year earlier. Prices fell 0.7 percent in Atlanta and 0.1 percent in Dallas.

Only three areas - Charlotte, N.C.; Portland, Ore.; and Seattle - posted year-over-year home price appreciation in October, with Charlotte posting the largest gain at 4.3 percent.

Those cities, however, saw declines when looking at October prices compared with September and August of this year.

"This shows we're in the middle of a housing recession, and it won't likely end until at least the middle of 2008 and maybe not until the next year," Maitland said.

The monthly index comes on the heels of September's S&P index that showed Tampa with the largest yearlong price drop, 11.1 percent.

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