TAMPA - Real estate agent Ken Brownlee's phone stopped ringing last month once clients figured they would be unable to close before an $8,000 federal tax credit expired.

Most of his buyers were first-timers looking for a sweet deal on a short sale or foreclosed home.

"They all want to grab a deal," said Brownlee, an agent with Keller Williams.

Those buyers now have another chance because Congress extended the program this month. Real estate agents say it could mean a boon for sales.

First-time buyers can get a credit up to $8,000, and other buyers are eligible for a credit of $6,500 as long as they have lived in their homes at least five years. Congress also expanded it to include buyers who already own homes.

Business picked up immediately, Brownlee said.

"As soon as it passed, I started to get a lot more phone calls and Web site hits on my listings," he said. "This tax credit will likely carry us through the normally slow season."

That's good news for the Bay area's fragile housing market. Real estate agents say the tax credit is essential for selling off inventory. Home prices have plummeted, and that has enticed buyers, but many still are on the sidelines.

Home sales in the Tampa-St. Petersburg-Clearwater area increased 20 percent in the third quarter, which ended Sept. 30. Experts credit the increase mainly to first-time buyers trying to take advantage of the tax credit.

The area saw 7,795 sales in the quarter, up from 6,502 during the same period a year ago, according to the Florida Association of Realtors. At the same time, the median sales price fell 17 percent to $140,400.

People want to take advantage of deep discounts, but they have to sell their existing homes to move up. With nearly half of the metro area's homeowners owing more than their homes are worth, many can't afford to move.

That's why the tax credit will help, said Stephanie LeFew, a real estate agent with Tampa Home Buy Realty. She's had a number of clients decide to stay in their homes because they can't sell for enough to justify a move.

"For some people, the credit will be just enough of a boost," she said.

Mike Larson, an analyst with Weiss Research, said home sales likely will continue to improve, even without the tax credit. He expects the credit to lure more people into the market.

"The credit is the icing on the cake, not the cake itself," he said. "What's really leading to improvement is that homes are affordable again. If you throw an expanded credit into a market that already has good fundamentals, the market will respond."

To take advantage of the credit, a prospective home has to be under contract by April 30 and the deal must close by June 30.

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