A majority of the 15 trustees of the University of the District of Columbia have indicated they will seek some way to oust President Robert L. Green at a special board meeting today in light of disclosures about Green's expenditures and pressure from Mayor Marion Barry to resolve the controversy.

At least 11 of the board members said in interviews or told colleagues that they favor firing Green or allowing him to resign. But some said that legal issues surrounding the financial settlement of the unexpired portion of Green's five-year contract could force them to delay action or place Green on administrative leave until an FBI investigation and a series of audits of university accounts are completed, according to university sources.

The board is divided, sources said, over whether to buy out a portion of Green's contract, which is due to expire in September 1988, or to ask that he leave with no further compensation.

Under the contract, Green, 51, is paid an annual salary of $74,900 and is entitled to the use of the university residence staffed with two housekeepers, and a university car. The contract does not guarantee that Green would be compensated in the event he is fired.

According to sources, Green has said he wants a settlement that would exceed his salary for the next three years.

However, several trustees said in interviews that they are unwilling to pay Green any money, while one indicated that $80,000 is the maximum the board should approve.

Green has not been in his office on the campus of UDC, on upper Connecticut Avenue NW, for the last two days. His spokesman, Gilbert Maddox, could not be reached for comment.

Green's personal attorney, Thomas Atkins of New York, was in Washington for meetings with UDC officials earlier this week, according to sources.

Meanwhile, the FBI has begun interviewing university officials and examining university records as part of a preliminary investigation to determine whether Green and other UDC officials misspent university funds.

"The investigation is continuing," Ron Dervish, an FBI spokesman, said yesterday. "At the present time, we are going through files and records."

UDC Trustee Joseph Webb, who asked the federal prosecutor to investigate about 20 issues involving UDC finances and who was the first board member to call for Green's resignation, said he was told by an investigator in the U.S. attorney's office that the investigation would continue even if Green resigns.

"If Green leaves today or tomorrow, that will not stop the investigation," Webb said.

A spokesman for the U.S. attorney declined to comment on his office's role in the investigation, although sources said the office has assigned an attorney to the case. Last week, U.S. Attorney Joseph E. diGenova said the questions raised by Webb were under "active review."

A week ago, five trustees said they favored Green's resignation. Disclosures during the last few days about Green's expenditures of university funds for personal travel and the purchase of flowers for friends appear to have influenced several trustees to shift their position on Green.

"On the basis of additional information that has come out this week, I am certainly moving in the direction of thinking that President Green has acted in a way that is inconsistent with his remaining in office," said one trustee, who earlier had said he was awaiting the completion of audits of university accounts. The trustee asked not to be identified.

The Washington Post reported this week that Green used the university's representation fund to pay for seven trips by Cassandra A. Simmons, a longtime associate and former student at Michigan State University. The Post had earlier reported that Simmons had received $37,200 in consulting fees paid by UDC since Green became president in September 1983.

Green also billed UDC for flowers he sent to his wife, Lettie, on Mother's Day.

University sources also said this week that audits being conducted of university expenditures would further damage Green's position with the board. Green has told university officials, according to sources, that an audit of the postsecondary education account will reveal that his wife traveled to Africa within the last year at university expense. The audit also will show that Green billed UDC for more than $2,000 in membership fees and dues at the Bethesda Racquet and Health Club, the sources said.

University sources said yesterday that Green also used the postsecondary account to pay for at least three more trips by Simmons, who was hired as a UDC consultant, to other cities and for her bills at several luxury hotels in Washington.

Barry said at a news conference Wednesday that he was calling for a quick end to the three-month old controversy because UDC "cannot survive a story a day to run the president away."

University sources said that although most of the trustees want to reach a final agreement with Green today, they may be reluctant to settle on a specific amount to pay him until the FBI investigation and audits are completed and there is an accurate measure of Green's alleged abuses.

Some trustees have indicated that they favor some compensation for Green to avoid further legal wrangling with him, according to sources.

The key players in the 11th-hour negotiations are board Chairman Ronald H. Brown; Green's lawyer Atkins; board member Herbert O. Reid Sr., the mayor's legal counsel, and Washington attorney Vincent H. Cohen, who was hired as special counsel to the trustees.

Barry, who is scheduled to leave tomorrow for a mayors' conference in Florida, said Wednesday that he intended to meet with the board before he left town to get a briefing "on what they have done or will do about the financial affairs of the university."

Several trustees said the mayor, who appoints 11 members of the board, should not interfere in the deliberations of the autonomous board.

The mayor has scheduled a news conference on an unrelated matter shortly before today's board meeting. A spokesman for the mayor said that Barry was not scheduled to attend the trustees meeting but would not rule out the possibility that he would go.

Without calling directly for Green's ouster, leaders of the faculty union yesterday urged the board to meet with faculty members to "chart out a plan of action for a new beginning."

Union leaders George Zachariah and Samuel F. Carcione said in a statement that "no person should be appointed in an acting or permanent position as president of the university without proper consultation and acceptance by the faculty." CAPTION: Picture 1, Cassandra A. Simmons . . . $37,200 in UDC consulting fees; Picture 2, Robert L. Green . . . under fire.