SAN FRANCISCO (AP) _ The U.S. Postal Service must pay $55,000 to a deaf employee who said she repeatedly submitted to a supervisor's request for sex because she feared losing her job, a federal appeals court ruled Tuesday.

Although the supervisor may not have said so, he ''implicitly conditioned the granting of specific job benefits upon (the employee's) performance of sexual favors,'' the three-judge panel of the 9th U.S. Circuit Court of Appeals said.

The court said the Postal Service, as the employer, was legally responsible for the harassment.

The ruling upheld the damages of about $55,000, plus retroactive sick-leave benefits, to Terri L. Nichols for a 2 1/2 -year period after the harassment during which she was unable to work.

Nichols, a night-shift mail sorter at the Salem, Ore., post office, said the harassment began in 1986 when her supervisor, Ron Francisco, followed her into a copy room one night and asked for oral sex. She said she resisted the request at first but eventually complied because she feared losing her job.

Similar incidents continued for about six months, Nichols said, with Francisco asking for sex after they had discussed her sick leave and attendance record, implying her work evaluations were at stake. At other times, she said, his requests came after she asked for time off.

After her husband filed for divorce in April 1987, Nichols said, she asked Francisco for a two-week leave, which she said he granted after a final sexual encounter.

She said she didn't report the incidents at first because she feared no one would believe her and she would face retaliation. Francisco was the office's only supervisor who could communicate with Nichols in American Sign Language.

After Nichols did tell what happened she was diagnosed with post-traumatic stress and granted federal disability benefits of 75 percent of her salary for 2 1/2 years. The damages she won included the final 25 percent of her salary.

Francisco, who denied the allegations, was fired by the Postal Service in October 1987 but reinstated by a government review board six months later.

Nichols now works at another post office in Oregon, said her lawyer, Elizabeth McKanna. She said Francisco has left the Postal Service.

Assistant U.S. Attorney Judith Kobbervig, who represented the Postal Service, couldn't be reached for comment.