Covington & Burling, the District's largest law firm and one of its most prestigious, has dropped South African Airways as a client after lawyers in the firm criticized its representation of the government-owned airline and students at Harvard, Yale and other law schools began boycotting Covington's efforts to recruit associates.

Covington partner Edward Dunkelberger denied that the boycott, which he termed "quite inappropriate," helped spur the move. He said the firm's 97 partners decided at a regularly scheduled meeting last week to stop representing South African Airways, which had been a client of the 225-lawyer firm for about 15 years.

Dunkelberger declined to specify the precise reasons for the firm's action, which he said had been under consideration for "a number of years." Citing "the increasing notoriety of the problems in South Africa," Dunkelberger said, "One would have to be a fool to think it was unrelated to the apartheid issue."

South African Airways officials declined to comment on the move, as did Covington partner Brice Clagett, who had been the airline's principal lawyer at the firm. The airline has flights to New York, but none to Washington.

Students at Harvard Law School organized a boycott at 17 campuses across the country, including American University, of firms representing South Africa. The boycotts were timed to begin at the start of the school year, when law firms annually campaign to attract the best and brightest students from the nation's top law schools for summer internships and full-time positions.

"We started thinking about it last year as a way that law students could express our feelings about apartheid and our desire not to be complicit," Lois Murphy, a second-year student and member of the Harvard Law School Anti-Apartheid Committee, said of the unusual tactic. "We feel it's important to participate in the growing movement to isolate the South African government."

Having the government-owned airline as a client is the legal "equivalent of selling krugerrands," said Jonathan Piper, who helped organize the effort at Yale Law School. "Representing an airline which is owned by the South African government means you're trying to save money for that airline, which means you're making money for the South African government."

The students targeted five firms that represent the South African government, of which Covington was by far the largest and the only one that conducts extensive recruiting at law schools. It appears that the other four continue to represent South Africa.

At Harvard, where Covington was the second most popular law firm last year in terms of the number of students signing up for interviews, 400 students signed petitions pledging not to interview with or take a job with any firm that represents South Africa, Murphy said.

At Yale Law School, where Covington lawyers conducted on-campus interviews last week, the number of students requesting interviews with the firm was down 20 percent from last year, according to law school spokeswoman Catherine Iino. After Covington telephoned The Yale Daily News with the news of its decision to stop representing the airline, the number of students interviewing with the firm returned to the previous year's level, she said.

Boycott organizers claimed credit for Covington's decision. But Dunkelberger said the tactic "really made the decision more difficult than it would have been" because "any partner that thought about it was aware of the fact that we would appear to be yielding to third-party pressure."

"Where lawyers or would-be lawyers are trying to compel other lawyers not to represent someone because they don't like them raised great concerns on our part," Dunkelberger said.

He added, however, that he believed it was ethical for Covington to stop representing the airline. Although "lawyers have an obligation to assure the availability of legal services to the public," he said, "that has not ever been interpreted as saying that any particular lawyer or firm has to represent any particular client."