WASHINGTON (AP) _ Florida's passionate and at times pugnacious Rep. Sam Gibbons announced his retirement Monday, joining the exodus of senior Democrats from Congress.

``I will not seek re-election. After 34 years in the Congress, I am ready to do something new,'' said Gibbons, ranking Democrat on the powerful Ways and Means Committee. That's the panel with jurisdiction over taxes, Social Security, Medicare, welfare and trade.

Gibbons, 76, said President Clinton called him Sunday night and tried to dissuade him from becoming the 26th Democrat to leave the House. Many are vacating Southern seats that Republicans have a good chance to capture.

Gibbons held his district, which includes Tampa and two-thirds of the surrounding county, by a 52-48 margin in the last election. His GOP challenger, former Naval Intelligence officer Mark Sharpe, is running again.

Four retiring Democrats including Gibbons would have been in line to become committee chairman had they been reelected and Democrats retaken control of the House.

The others are Kika de la Garza, Texas, Agriculture; Cardiss Collins, Illinois, Government Reform and Oversight; and Sonny Montgomery, Mississippi, Veterans' Affairs.

Only 15 House Republicans have announced plans to retire or run for higher office. Rep. Toby Roth, first elected to Congress in 1978, became the latest with an announcement Monday from Appleton, Wis., in his district.

Roth, 57, did not disclose his plans and said he was leaving because ``it is the right time for me to come home.'' He is chairman of the House International Relations economic policy and trade subcommittee.

Gibbons said he plans to teach, serve on boards and work for President Clinton's re-election. He said he discussed with Clinton working with the Office of the U.S. Trade Representative.

As a young man, Gibbons parachuted into Normandy on the night before D-Day. After the war, he practiced law and served 10 years in Florida's House and Senate before election to Congress in 1962.

In 1965, President Johnson chose the relatively junior Gibbons as floor manager of crucial bills creating Head Start, the Job Corps and other Great Society programs.

His final term has been spent trying to preserve many of those same programs as Republicans controlling the House for the first time in 40 years seek to dismantle them.

During almost 14 years as second-ranking Democrat on Ways and Means, Gibbons was overshadowed by its domineering chairman, Rep. Dan Rostenkowski, D-Ill.

He finally got his chance at the helm in June 1994 when Rostenkowski was indicted on charges he misused his office and had to step down. Gibbons helped shepherd to enactment a new world trade pact under the General Agreement on Tariffs and Trade.

But it was as a leader of the House minority that the low-keyed, good-humored lawyer blossomed into a passionate, sometimes angry, defender of Medicare, Medicaid and welfare.

During debate on welfare in March on the House floor, Gibbons tried to shout down boisterous Republicans. ``You all sit down and shut up,'' he bellowed. In September, when a committee scheduling dispute spilled over into an angry shouting match in a Capitol hallway, Gibbons squared off with Rep. Bill Thomas, R-Calif., 22 years his junior, and tugged his tie.

After Gibbons, Rep. Charles Rangel of New York is the next most senior Democrat on Ways and Means. A 65-year-old liberal, Rangel represents Harlem.