WASHINGTON--A bitterly divided House voted Wednesday to cut off U.S. military support for Nicaragua's contra rebels, rejecting President Reagan's aid request in the hope of fortifying the Central American peace process.

The 219-211 vote, culminating six years of overt and covert military support for the rebels fighting the leftist Sandinista government, killed Reagan's request for $36.2 million in new aid to keep the contras alive as a fighting force through June.

It was a serious defeat for the president, who had lobbied hard on the issue for two weeks and has put the contras among the top foreign policy priorities for his final year in office. Only a day earlier, Reagan had offered one final compromise giving Congress more say in the military aid. He argued that failure to extend aid would strengthen communist influence in the hemisphere.

The White House issued a statement saying it was disappointed the House "did not vote to keep pressure on the Sandinistas during the peace process."

"We thank our many supporters in Congress who worked so hard on behalf of this issue. We will continue consultations with these congressional supporters and others concerning the future of the resistance and the peace process," said Presidential Spokesman Marlin Fitzwater.

A contra spokeswoman in Miami termed the vote "a serious setback in our struggle for freedom and democracy."

"The vote does not mean we will stop," said Marta Sacasa, spokeswoman for the Nicaraguan Resistance, the umbrella group known as the contras. She said contra leaders would "reassess possible strategies" but added, "there's no way a U.S. vote is going to change our determination or will. We will just have to do without."

Nicaragua's ambassador told Managua's Radio Sandino that the vote was "nothing more than recognition of the sentiments of the majority of the North American people."

"We hope that based on this vote we can move ahead with the Central American peace plan, end the war and fulfill in all good faith what the peace plan includes," said Ambassador Carlos Tunnermann.

In the voting, 12 Republicans sided with 207 Democrats to defeat the president's aid request. Forty-seven Democrats joined 164 Republicans in voting for the president's package.

"Today's vote is the end of a chapter," said House Majority Whip Tony Coelho (D.-Calif.). "The contra policy is the past. Now we can deploy America's greatest strengths, from aid and trade to diplomacy, to stoke the flames of liberty and secure the future for Central America."

But Republicans warned that the action would relieve part of the pressure on Nicaraguan President Daniel Ortega which they contend has forced him into recent concessions. The aid cut-off would allow Managua to slip backwards into renewed repression, the president's congressional supporters charged.

"The issue of Nicaragua and Central America will not go away," said House Republican Leader Robert Michel of Illinois.

"If you vote this package down, you'd better be prepared to bear the consequences," Michel said. "And who among you is smart enough to predict the path on which Daniel Ortega will take you?"

Current aid to the rebels expires February 29, and Democrats pledged to hold another vote before the month is out on an alternative package of purelyhumanitarian aid to the rebels. They would thenfollow that up with a new emphasis on economicdevelopment aid for countries in the region thatabide by terms of a five-nation peace accord.