Trustees of the University of the District of Columbia named a veteran professor and administrator on Friday to serve as temporary leader of the school following their vote this week to fire President Allen L. Sessoms.

Rachel Petty, a psychology professor who has previously served as acting vice president for academic affairs and dean of UDC’s College of Arts and Sciences, will run the university for several weeks as interim chief operating officer until an interim president is named, UDC officials said.

The Board of Trustees of the city’s public university voted Wednesday to fire Sessoms, 65, without cause. He had held the job since September 2008. Under his contract, Sessoms will be eligible for $295,000 in payments after his termination, which takes effect Jan. 18.

The abrupt transition comes amid debate over proposed budget cuts at the struggling 5,490-student university and the future of its subsidiary community college, created in 2009.

Elaine A. Crider, chairwoman of the governing board, declined to elaborate on why Sessoms was fired.

“ ‘No cause’ is about the best answer you’re going to get,” Crider told reporters Friday afternoon at UDC headquarters on Connecticut Avenue NW. “We’d rather talk about where we’re going, not where we’ve been.”

Crider added that she is committed to moving the community college, headquartered on North Capitol Street, toward independence. That echoes the view of Mayor Vincent C. Gray (D).

Asked whether Gray had a role in firing Sessoms, Crider said the trustees acted independently. “We don’t need the mayor to influence us, and he didn’t,” Crider said.

The 15-member board is made up of 11 mayoral appointees, three elected alumni and a student member, according UDC spokesman Alan Etter. He said Crider was appointed by Gray’s predecessor, Adrian M. Fenty (D).

On Thursday, Gray told a television interviewer that he was not directly involved in the board’s action. But the mayor sent the D.C. Council a budget request on Monday, two days before Sessoms was fired, asking legislators to transfer $350,000 to the university for “personal services for strategic UDC personnel.”

A senior Gray administration official confirmed Thursday that the request was meant to provide funding related to Sessoms’s departure. The official called it a “buyout of his contract” rather than a severance payment.

Gray, who after his 2010 election was considered an ally of Sessoms, had tempered his enthusiasm for the UDC president in recent months amid questions about how aggressively the university was moving to cut costs and reduce its dependence on city subsidies.

As interim chief operating officer, Petty, 69, who has worked at the university for more than three decades, will have a salary that is comparable to what the UDC provost makes.

Officials said that translates to $229,000 a year. “I’m confident the board and I can work together,” Petty said. “It’s a very short time frame.”

Mike DeBonis contributed to this report.