Rep. Lindy Boggs (D-La.), an influential figure in Washington and Louisiana political circles for half a century, announced in New Orleans yesterday that she will retire from Congress at the end of this year.

Boggs has represented her New Orleans district in the House since 1973, when she won a special election to replace her husband, Hale Boggs, who then was serving as House majority leader. He was aboard a plane that was lost in Alaska in 1972. He had represented the Louisiana district since 1940, and his wife had managed his campaigns before winning the seat herself.

"Today I am announcing that this chapter in my service to the public is ending," said Boggs, in announcing her retirement. But, she said, "this is not the end of my career. I will continue to actively participate in community activities here and in Washington."

Her announcement prompted a particularly warm and affectionate goodbye from House Speaker Thomas S. Foley (D-Wash.), who said, "never in my 25 years in the U.S. House of Representatives have I felt greater regret at the departure of one of my colleagues."

Foley credited Boggs, 74, with bringing "unparalleled intelligence, grace, courage and charm" to the House. A member of the House Appropriations Committee, where she has been effective in ensuring federal aid is provided to her district, Boggs had been favored to win another term. A majority of voters in her district are black, but Boggs, who is white, has consistently won re-election with large margins.

Officials at the Democratic Congressional Campaign Committee flatly predicted yesterday they will be able to keep Boggs's district in the Democratic column this November.

Among the Democrats who have announced they will or might run in the Oct. 6 primary are Jon Johnson, 41, a college professor; Marc Morial, 32, a lawyer and son of former New Orleans mayor Dutch Morial; and William Jefferson, 43, a state senator and two-time unsuccessful mayoral candidate.