Mayor Marion Barry said he would urge two key trustees of the University of the District of Columbia to resign in an effort to end a campus protest that led to the cancellation of classes yesterday and today for the 12,000 students of the city-operated institution.

Despite Barry's promise, made during a closed 4 1/2-hour session with protest leaders, several hundred students remained in two UDC buildings they seized Wednesday and from which they issued an ever-escalating series of demands, including that Barry remove the 11 trustees the mayor is empowered to name to the 15-member board.

The storming of the buildings came after years of turmoil at UDC, a 13-year-old school plagued by confusion in academic programs, scandals in athletic programs and rapid turnover in the president's office, where five men have served since its founding. Much of the students' ire has been aimed at the board of trustees for allegedly allowing the instability.

At a news conference outside one of the occupied buildings on Connecticut Avenue NW, Barry said that although D.C. law enables him to appoint 11 trustees after consultation with the D.C. Council, he has no authority to remove them. But Lurma Rackley, his spokeswoman, said Barry had agreed to ask Nira H. Long, chairman of the trustees and one of the 11 he appointed, to step down.

He will also ask Cynthia D. Smith, a student elected to the board by her classmates, to resign, Rackley said. Long and Smith have been focal points of students' criticisms.

The students believe that Smith has failed to keep them informed of the board's actions. Long, they said, declined three times to call a special board meeting to discuss the students' concerns with them.

Barry will tell Long and Smith that "maybe {resignation} is the best thing to do" to end the protests, Rackley said. Neither Long nor Smith could be reached for comment.

Rackley said Barry will tell the 10 other city-appointed trustees that the students would like them to resign by March 31 but that, unlike the request to Long and Smith, he would not necessarily endorse that demand. "He is passing a message to those 10," Rackley said.

Last night, several board members said Barry had contacted them to pass along the students' request and to ask that all the board members meet with him at the campus this morning.

Rackley said the March 31 resignation date was proposed to enable the District's new mayor, who will take office Jan. 2, to evaluate the 10 other trustees to determine whether to accept their resignations. In addition, students might decide that some of those 10 should remain as they open discussions with university officials about the rest of their demands.

Barry told the protest leaders he would tell them today what responses he receives from the trustees. It was unclear, however, whether students would end the protest if Long, Smith and the 10 other trustees agree to do what they want. The three other trustees are young alumni and have not been the object of student unhappiness.

In interviews, several trustees expressed sympathy for many of the students' demands, which include longer library hours, an Afrocentric curriculum, better buildings and a task force to revise athletic programs.

They also want the university to renounce its recent acceptance of "The Dinner Party," a work of art that features dinner place settings, a few of which some critics describe as depicting female genitalia. Students say they are not offended by the work itself but by the fact that it threatens $1.6 million in federal funding because some members of Congress have called it obscene.

Joseph Webb, one of the alumni trustees, said the demands "were extremely legitimate, and I remain supportive of the vast majority of the issues that they have raised." Webb added, however, that a mass resignation of the trustees might threaten UDC's accreditation and he would prefer changes to occur gradually.

Likewise, board member A. Knighton Stanley said of the demands that he didn't "have too much problem with any of them," though he said he would be opposed to rejecting "The Dinner Party" because "you have the issue of academic freedom and the interference of Congress in the affairs of the university."

Stanley, who was interviewed before Barry made his statements about the board, said he believed the specific demands were only a reflection of concern about UDC's fate in recent years, symbolized by the turnover among presidents. "They fear that they're going to go through four years . . . and come out and have a degree that's worthless," Stanley said.

"What we have here is a hastily put together set of demands which is a general reflection of anxiety students have about the university: whether it's being governed with strength, whether anyone is in control of it," he said.

Donald Hughes, a freshman political science major who stood with the crowd outside the occupied buildings, said he supported the student takeover because of problems the administration has had in providing services.

"Sometimes it's worse than paying a ticket or getting a driver's license at the DMV," he said.

Staff writer Steve Twomey contributed to this report.