Women denied employment or promotion because they refuse to give sexual favors to superiors can seek redress under federal civil rights legislation, the U.S. Court of Appeals ruled yesterday.

In what appears to be the first federal appeals court ruling on the question, the court said women subjected to requests for sex fom their bosses are protected by Title VII of the Civil Rights Act of 1964 and the Equal Employment Opportunity Act of 1972.

"We cannot doubt that Title VII intercepts the discriminatory practice charged here," wrote Circuit Judge Spottswood W. Robinson III in an opinion in which Chief Judge David L. Bazelon concurred and in which Circuit Judge George E. MacKinnon concurred in a separate opinion.

The judges noted that various U.S. District Courts had reached different results in similar cases.

The case the appeals court here decided was a suit brought by Paulette L. Barnes, a black woman. She said she had been hired by the Environmental Protection Agency as a GS-5 administrative assistant. She said that at her hiring interview she was promised promotion to grade GS-7 "withing 90 days," according to the court record.

Shortly after she began work, the court said, her boss repeatedly suggested that "if she cooperated with him in a sexual affair, her employment status would be enhanced," according to her complaint.

When she persisted in her refusals, he said, her job was abolished and she was reasigned elsewhere in the agency as a GS-5. Her former job was elevated to grade GS-12 and given to a white woman, the court said.

After numerous administrative hearings in which she asserted that she had been the victim of racial, rather than sexual, discrimination, she filed suit in U.S. District Court here.

The District Cout held that her boss's alleged retaliatory action on her refusal to engage in an "after-hour affair" was "not the type of discriminatory act contemplated by" the federal civil rights law.

In reversing that ruling, the appeals court said: "But for her womanhood, from aught that appears, her participation in sexual activity would never have been solicited.

"To say, then, that she waas victimized in her employment simply because she declined the invitation is to ignore the asserted fact that she was invited only because she was a woman subordinate to the inviter in the hierarchy of agency personnel."

The court directed that the case be returned to the District Court so that Barnes would have a chance to prove her claim of sexual discrimination.