Mayor Marion Barry summoned his cabinet and other top aides to an extraordinary meeting in the D.C. Council chamber yesterday, where he unveiled anticorruption measures with a warning that public concern about government ethics threatens home rule.

The mayor, who said he was acting on recommendations of an Ethics Strike Force he appointed in April, announced he would name an ethics ombudsman within a week to encourage employes to report misconduct.

Citing a "mass of confusion about the laws and regulations," Barry also said he would refine the city's conflict-of-interest regulations and initiate ethics training programs for city employes.

At one point during the 45-minute speech, Barry looked back on nearly 15 years as an elected official and declared with emotion, "A number of things have been said about this mayor -- some good, some bad. But one thing that has never been said is that . . . I am a thief."

Barry's proposed changes would consolidate the District's conflict-of-interest regulations to make it easier for employes to understand them, but would not change laws or criminal penalties. Restrictions on employes' right to do business with the city after leaving its employ would be expanded to include a larger segment of the city's work force.

Barry used the unusual session to acknowledge directly his concern about the impact on his administration of recent investigations into alleged corruption and to publicize his response. A candidate for reelection, he stressed in an interview afterward that he was "speaking as mayor -- I was not speaking as Marion Barry, candidate for mayor."

Several other candidates for the office saw the speech in a different light. "It's purely political," said independent candidate Brian Moore.

Barry's ethics initiative, presented to a standing-room-only crowd of about 300 D.C. officials who received wallet-sized cards spelling out "District of Columbia Government Integrity Standards," comes after a series of disclosures about alleged malfeasance by D.C. officials.

Last December, Barry's longtime aide and former deputy mayor Ivanhoe Donaldson pleaded guilty to federal fraud and cover-up charges. Since then, several other high officials, including former deputy mayor Alphonse G. Hill and former employment services chief Matthew F. Shannon, have resigned amid charges of wrongdoing.

The 22-member Ethics Strike Force grew out of a cabinet retreat -- known as an "advance" in Barry administration parlance -- held just weeks after the Hill and Shannon resignations.

"Coming out of the advance, we couldn't discuss anything without discussing ethics, the perception that the government is corrupt," said Carol B. Thompson, Barry's chief of staff. "I think the mayor feels this issue in his gut."

The strike force, headed by Herbert O. Reid Sr., the mayor's legal counsel, included City Administrator Thomas Downs; Dwight S. Cropp, director of the Office of Intergovernmental Affairs; Inspector General Vernon S. Gill; Police Chief Maurice T. Turner Jr.; Joseph P. Yeldell, director of the Office of Emergency Preparedness, and other top aides.

Barry's new move drew a mixed response from government officials and mayoral challengers. Mattie Taylor, a former school board member and Democratic candidate for mayor, termed it "a whole lot of whipped cream and hot air. Until this government is cleaned at the top, nothing is going to change."

D.C. Council member John A. Wilson (D-Ward 2), saying he is dismayed that the new moves weren't taken "years ago," worried that the D.C. government is "playing Russian roulette with home rule . . . . I think if something isn't done quickly, the Congress might start investigating the government."

Wilson has proposed the formation of a special council committee to investigate corruption.

Council Chairman David A. Clarke, author of a rival proposal to establish a new investigative agency for corruption, yesterday commended the mayor for disseminating ethics regulations but urged formation of the new agency.

And council member Carol Schwartz (R-At Large), who is challenging Barry for mayor, pronounced the initiative "a lot of show. I am not sure the substance is there."

Barry, in discussing his ethics initiative, said the ombudsman would not have subpoena power but would be free to report findings to appropriate law enforcement agencies as well as the council, the public and the mayor. He said he would name a person of stature, perhaps a retired member of the judiciary.

"The ombudsman would not report directly to me . . . would not be under my control," Barry said. Other elements of his proposal include:A new biweekly "Procurement Digest" listing all upcoming procurement deals and contract awards that have been made. Appointment of ethics counselors to advise employes of every government agency. A symposium on ethics planned for next fall to include government officials, the media, academicians and law enforcement authorities who will discuss the "causes of ethical problems in municipal government and . . . suggest targeted solutions." New regulations to control the so-called "revolving door" of government employes who capitalize on their former positions when they move to the private sector.

"It is important that the public does not see the government as a revolving door," said Barry, several of whose former top aides have been criticized for obtaining consulting contracts with the government. Possible changes in the method of screening future cabinet officials. Barry said that if he wins election to a third term, he may require his cabinet officers to disclose to him their tax returns for the last five years in an effort to detect possible conflicts of interest.

"I would be willing to submit my own to my legal counsel," added Barry, who has repeatedly declined to publicly disclose his tax filings.

The mayor acknowledged to the gathering of high officials, which included all his political appointees and D.C. procurement officials, that the allegations of corruption are difficult for his administration to overcome.

"The issue is hard to get at," he said, comparing it with the relative ease of a city service issue like fixing potholes. "It is feeling, it is visceral, it is emotional."

But, he added, "We think that this program is going to get us ahead in terms of the public perception that we are not doing enough."