Mayor Marion Barry, apparently responding to reports of dissatisfaction among whites in the city's uniformed services, asserted yesterday in announcing police promotions that race would play no part in advancement in the city government.

"Race -- I'm going to put that to rest," the mayor, a former black community activist, said at a news conference at police headquarters. "Race is not going to matter in promotions in the police department, fire department or anywhere else in the city government."

To underscore his message, Barry pointed out that seven whites were among the 12 persons whose promotions to high-ranking police posts were announced yesterday. One of the 12, Joyce Leland, who is black, is the first woman in the department's history elevated to the rank of inspector.

Police Chief Burtell M. Jefferson, also black, endorsed Barry's assertion that the white officers "have just as much chance" at promotion as blacks.

Although race would not matter, Barry said, "what is going to matter is residency (in the District). "That's going to be a very important factor in promotions in the future."

Many members of the city's police and fire departments say they cannot afford to live in the city, and live instead in the suburbs. Barry has long asserted that District residents better understand the city's problems.

Many of the promotions were designed to fill gaps at top levels caused by a wave of retirements anticipated at the end of this month that marks the largest single departure ever of top police officials.

The exodus was spurred by a combination of higher retirement pay and long-brewing disgruntlement with the city's black administration.

Both white police and white fire officials have said that they are leaving because they believe opportunity for advancement is limited because of their race.

They have said they think they are being shunted from the promotional track and from policy-making positions by a City Hall administration committed to accelerating black promotions in the uniformed agencies that have traditionally been dominated by whites. The city's population is 70 percent black.

On the capabilities of the police in the wake of the rash of retirements, the mayor said "we're going to make sure that there are enough people on the street to protect the city."

He said he wanted "to assure the people of our city that our new leadership is going to be very good. We want to maintain and we will maintain front-line crime fighters."

Barry said he would continue to keep more than 60 percent of the department's uniformed strength on the streets and added that it might be necessary to use civilians in a number of desk jobs to free uniformed officers. n

Barry and Jefferson concluded last week that savings made possible by retirements and other reduction measures would make unnecessary the proposed layoff of 204 officers that was part of the mayor's plan to deal with the city's budget crisis. If Congress votes money originally earmarked in the House to help keep the 204, more officiers might be hired, Barry said yesterday.

In addition to John Conner, whose promotion to deputy chief and head of the special operations department division was announced last week, two new deputy chiefs were named. They were Melvin A. Winkelman, to head the third district, and Isaac Fulwood Jr., to add planning and data processing to his job as head of financial management. Deputy Chief Alfonso Gibson was made chief of detectives.

In addition to Leland, three other captains were promoted to inspector and made night supervisors, responsible for the department when the chief is not on duty. They are Thomas L. Carroll, Leonard A. Maiden and Martin H. Niverth.

The five other new inspectors and their posts are: Wilfred K. Coligan, head of the morals division; Fred W. Raines, chief of investigative services; Melvin C. High, disciplinary review officer; Max J. Krupo, head of fleet management, and Bobby J. Wallace, head of labor relations.