D.C. Mayor Marion Barry, facing increasing demands to improve the city's troubled ambulance service, stripped Fire Chief Theodore R. Coleman of authority over the service yesterday and placed it under the direct control of City Administrator Carol B. Thompson.

Barry, with Coleman silently standing by during a news conference, said he has told Coleman to issue an order to fire department officials requiring them to cooperate with John M. Cavenagh, the city's civilian ambulance director. Cavenagh, who will report to Thompson, has clashed with Coleman on several occasions since his appointment last fall.

Barry also appointed senior aide Joseph P. Yeldell to a new position as staff assistant to Thompson to make certain fire officials comply. Yeldell, the director of the Office of Emergency Preparedness, has been working behind the scenes unofficially for several months to minimize Coleman's interference with Cavenagh, aides to Barry said.

The high-level shuffle came as Barry was being pressured by D.C. Council members and his own staff to force Coleman to retire or cede control of the ambulance service, which for now will remain as a unit of the fire department.

"There was no reason to fire {Coleman}. Ambulance service is only part of his job," said one Barry aide. "But {the mayor} knew the situation was reaching a crescendo, he had to do something."

"The key point is that the chief is not in charge {now}," another aide said. "Effectively, what we're trying to do is get the chief out of the ambulance business."

The mayor would not allow Coleman to answer questions at yesterday's news conference and the fire chief later refused to talk with reporters as he left the District Building.

Reaction to Barry's move was swift but cautious, with most council members and leaders of the city's medical community praising the changes while warning that much more needs to be done to correct years of poor emergency ambulance administration.

Council Chairman David A. Clarke, however, was highly critical, saying Barry's action created a "scrambled eggs of government" in which there would be no clear line of authority between the fire department, which retains control over fire and ambulance dispatchers, and ambulance crews that must work with them and other firefighters at emergency scenes.

"I think the situation will get worse rather than better," he said.

Thompson, who is in her first full week as city administrator, said Coleman's order to officials in the fire department will make it clear -- particularly to dispatchers, who play a crucial role in directing emergency crews -- that they must cooperate with ambulance service personnel. Thompson said it would be technically impossible to switch immediately to a separate dispatcher system for ambulances.

Council member Jim Nathanson (D-Ward 3), one of three council members who had called for the removal of Coleman, said, "I see tremendous substance in this decision. I'm very satisfied with the new management team. Now the ambulance director is going to be allowed to direct the service."

Dr. Vincent Roux, medical director of Howard University Hospital and chairman of the Mayor's Advisory Committee on Emergency Medical Services, warned that "this cannot be lip service. We still must have complete cooperation and necessary resources to improve."

Barry's reorganization plan came after three weeks of increasing criticism of the ambulance service, most of it directed at Coleman. The advisory committee voted last week that it had "no confidence" in Coleman's ability to manage the ambulance service.

The service has been plagued by complaints of slow response times, sloppy dispatching and poor training.

In addition to those complaints, each member of the city's Paramedic Review Board threatened to quit last week, citing "grave concerns" about the lack of cooperation it receives from the fire department. The board, which certifies paramedics, said fire department neglect had made it impossible for them to competently perform their duties.

Barry announced at the news conference yesterday that he will award an emergency city contract to a private group, the Consortium of District of Columbia Hospitals, to train much-needed paramedics to staff the city's ambulances. He also said he would soon submit legislation to speed the hiring of paramedics by exempting them from the city's residency law.

Barry said he acted yesterday because "it takes Chief Coleman out of the situation of being viewed as the problem." Barry praised Coleman as a veteran firefighter and indicated he would remain as chief at least through later this year.

Barry said numerous improvements in the ambulance service have been made over the past year, but said, "Nevertheless, recent incidents indicate that other actions are needed" and said the perception persisted that the ambulance service was not adequate. Barry insisted that "90 to 95 percent of the time" the service "works well, very well."

Aides to the mayor said yesterday that Barry had struggled with the Coleman decision for several weeks and finally made up his mind to take action after returning Monday from the Super Bowl in San Diego.

Council Chairman Clarke said he met with Barry to discuss the issue Tuesday. Council member John A. Wilson (D-Ward 2) sent a letter to Barry on Wednesday urging him to take action.

One assistant to the mayor said several "brainstorming sessions" were held this week and that aides were still "fine-tuning the decisions" just hours before they were announced. Yeldell, Thompson and other aides have been meeting as an advisory group for several weeks.

Aides to Barry credited him with devising the compromise to keep Coleman but to remove him from any line of authority for the service. The move settles at least for now a sensitive political issue for the mayor.

"There was a real concern, too, by the mayor and his aides that this issue would become very a very divisive issue in the community," one official said. Some political figures, including council member Wilhelmina J. Rolark (D-Ward 8), had cast support of Coleman as a racial issue and, the aide said, the mayor did not want to make that situation worse.

Coleman, who is black, has been the frequent target of criticism by leaders of the fire department union, whose leadership includes prominent white spokesmen.

Rolark, chairman of the Judiciary Committee and a strong defender of Coleman's, said at a rally for Coleman yesterday that she was satisfied with Barry's action because Coleman remains as head of the fire department.

Rolark said Coleman should not be singled out for criticism. "Don't point all your ugly fingers of scorn at one person. It's not a one-person thing," she said in an interview with WRC-TV (Channel 4). "And I'm saying that part of the reason those fingers are pointed is because of his color and I know that I'm right."

Council member Betty Ann Kane (D-At Large), who showed up at a separate rally of blacks and whites opposing Coleman, had said on Thursday that race was not an issue.

"People who say you can't change {the situation} because he's a black fire chief are overlooking the fact that the people who are dying are black," said Kane, who also has called for Coleman's resignation.

Capt. Ted Holmes, spokesman for the fire department, said that Coleman remains angered by recent criticism about his management of the ambulance service. "Obviously, he's very disappointed that it had to come to this," Holmes said.

"He still believes a misperception has caused this, but he's a big enough man to accept what has happened."

In the past two years, two city task forces and an outside medical consultant have recommended major policy and procedure changes to improve the District's service, but most task force members said in recent interviews that few of their recommendations have been implemented.

Since 1986, nine persons have died after city ambulances were slow to reach them, though no official link has been made between the delays and their deaths. On Jan. 17, Mozone Kelly of Northeast Washington died after an ambulance took nearly 40 minutes to arrive at his home.Staff writer Athelia Knight contributed to this report.