A D.C. Superior Court jury has awarded $546,019 to Nail H. Ozerol, a former assistant professor who sued Howard University after he was fired by its medical school.

The verdict, which was handed down late Friday, came after a seven-day trial in which Ozerol testi fied that he had been promised tenure and the rank of associate professor before he agreed to come to the university in December 1980. Several Howard officials testified that the university made no such promise and said Ozerol was only appointed to serve in a temporary position financed by a federal grant.

Ozerol, 53, is a Turkish national with a doctorate from the University of Illinois in food and nutritional sciences. He served at Howard as an assistant professor in the international health program until he was fired in June 1982.

Yesterday his lawyer, John M. Clifford, said Ozerol, who lives in Rockville, has been unemployed since his dismissal. Clifford said the damages were based on what Ozerol might expect to earn until age 65.

The case is the latest in a series of jury verdicts and out-of-court settlements in suits brought against Howard University by dissatisfied employes over the past three years.

Richard P. Thornell, Howard's general counsel, said the university had asked Judge Reggie B. Walton to set aside the verdict on the grounds that it was not supported by the evidence or to grant a new trial because the damages were excessive.

Clifford said Ozerol testified that tenure was promised to him by Dr. Calvin Sinnette, an assistant to Howard's vice president for health affairs. Clifford said Dr. Alonzo Gaston, former director of the international health program, testified he heard Sinnette make the promise.

However, Thornell said that Sinnette testified that he did not make such a promise and that Dr. Carlton P. Alexis, the vice president for health affairs, said such a promise would be against university policy.