Georgetown University cannot refuse to "officially recognize" gay student organizations on the basis that homosexuality is a violation of Catholic beliefs, a three-judge panel of the D.C. Court of Appeals ruled yesterday.

However, in an unusual move, the full Court of Appeals immediately announced it will rehear the case. That decision keeps yesterday's ruling from taking effect, and requires the parties to reargue the case before a final ruling is made.

Despite the order for a rehearing, lawyers for the gay student organizations yesterday praised the panel's decision, hailing it as a significant milestone in the history of the homosexual rights movement.

"It is a very, very important victory for people interested in gay rights," said lawyer Richard Gross, who argued the case before the three-judge panel, "because for the first time a court has said that the elimination of discrimination against gay people is as important as the elimination of discrimination on the basis of race or sex."

A Georgetown spokeswoman said the Catholic-run university had decided to withhold comment until a decision is made by the full court.

"We certainly do not consider it a defeat," said Nancy Preiss, one of the lawyers representing Georgetown. "This takes us back to square one, and we are gratified that the entire court agreed to hear the case."

In its arguments before the panel, lawyers for Georgetown did not deny that the university discriminated against two gay student groups whose applications for official recognition were denied more than six years ago.

Instead, Georgetown argued that it had a constitutional right -- that of the freedom of religion -- to decide to withhold special privileges from groups whose activity conflicts with Catholic teachings.

But in a 2-to-1 decision written by Judge John M. Ferren, the three-member panel agreed with arguments by the student groups' lawyers that Georgetown had violated the District's 1977 Human Rights Act, which prohibits discrimination based on "sexual orientation."

The District's interest in enforcing the Human Rights Act, wrote Ferren, "substantially outweighs" any intrusion on Georgetown's "exercise of its religious beliefs."

"The Human Rights Act requirement that Georgetown officially recognize gay rights groups on a nondiscriminatory basis does not necessarily imply that the University administration is spreading, let alone affirming, gay rights views," wrote Judge Ferren. "Enforcement of the Human Rights Acts means something less -- something attentuated: that certain student groups in a pluralistic university environment must have nondiscriminatory access to Georgetown's facilities to publicize messages they ascribe only to themselves, not to the university."

The case, which has drawn nationwide attention, began in April 1980 when the two groups, Gay People of Georgetown University and the Gay Rights Coalition, sued the university after it denied them the right to receive university funds, subsidized office space or permission to use Georgetown's name. In March 1981, a D.C. Superior Court judge concluded that the university was in violation of the 1977 Human Rights Act.

But in October 1983, another D.C. Superior Court judge, Sylvia Bacon, ruled that Georgetown could withhold privileges from the two groups because its Catholic beliefs were protected by the First Amendment. It was that ruling that the three-member panel rejected yesterday.

In most cases, the full Court of Appeals rehears a case only after a three-member panel has filed an opinion and one of the parties to the suit has requested an "en banc" hearing -- that is, before the full court -- Alan Herman, clerk of the court, said yesterday. Yesterday's immediate announcement of a new hearing by the full court was extremely unusual and was generally taken as an indication of the court's interest in the case.