David L. Gunn, former head of the New York City transit authority, is expected to become Metro's new general manager, sources said yesterday.

Metro's board has offered Gunn the job and the two sides are completing negotiations on salary and benefits, the sources said. An announcement is possible as early as this week, they said.

"He's their unanimous choice," a source close to Gunn said yesterday. "From everything I've heard, they are down to the final stages."

After learning yesterday that Gunn has told friends that he is the leading candidate for the Washington job, Metro board Chairman Hilda H.M. Mason said, "He was not supposed to do that. We have not worked any kind of agreement with him."

Gunn, 53, who was president of the New York transit authority from 1984 to March 1990, could not be reached for comment yesterday.

He has previously said he quit the New York job because he had become weary and wanted to take some time off before accepting a new position. He has spent much of the last year on his farm in Nova Scotia.

If Gunn becomes Metro's fifth chief executive, he would take over at a time when Washington's rail and bus system is facing several problems.

Metro is cutting costs and jobs to make up a $12.5 million budget deficit this year, and the board is planning steep fare increases. Ridership has fallen, and the local governments that support the system are having financial troubles. Buses, trains and stations are aging and will require increasing maintenance.

Gunn is known for his enthusiasm for his work, and won the respect of many New York riders by not buying a car or using an agency automobile during his tenure there. He used the subway for almost all personal and business trips.

He would replace Carmen E. Turner, who left the regional transit agency in December to become the day-to-day manager of the Smithsonian Institution.

Turner made $109,000 a year when she left Metro. Gunn was paid more than $140,000 a year in New York.

Metro board member Mary Margaret Whipple of Arlington would not confirm that the board has picked Gunn. Whipple said the board is still "in the process of making a final decision . . . . It's just not done yet."

However, some of Metro's senior managers already have been discussing what will happen after Gunn's arrival, a source in the agency said.

Gunn, one of the most prominent figures in mass transit nationally, was the favorite of many Metro board members from the start. The main question was whether he was interested and available. He also has been general manager of the Philadelphia transit system and was operations director of the Boston transit agency.

In New York, which has the nation's largest transit system, Gunn was credited with turning around subway operations, introducing new equipment, improving maintenance and cleaning up the notorious graffiti that scarred the system. When he left, the New York Times called him "The Man Who Saved the Subways."

But bus and subway ridership lagged even as Gunn promised to attract large numbers of new riders. Gunn blamed some of that on the economic downturn, which has affected all transit systems, including Metro.

Fares were increased under Gunn's tenure, an issue he will face if he becomes the Metro chief. Metro's board is discussing annual increases in fares, including an average 18 percent across-the-board increase starting July 1. New York riders paid 75 cents a trip when Gunn took over; the fare when he left was $1.15.

If he becomes Metro's general manager, Gunn will be joining a smaller transit system than New York's. The New York bus and rail system carries more than 5.2 million passengers a day; Metro riders take about 1 million bus and rail trips a day.

The New York system employs about 50,000 people, compared with about 9,000 Metro employees. New York has 6,200 rail cars operating over 705 miles of track on 25 lines through 463 stations. Washington's system has 660 rail cars operating on 70 miles of track, four lines and 64 stations.

Whipple said the board completed interviewing candidates last Thursday, and said no women were among the finalists. Former D.C. city administrator Carol B. Thompson and New Jersey transit chief Shirley A. DeLibero were mentioned early as possible candidates, but both sent word that they were not interested.

From an initial list of about 40 candidates, the board narrowed its search to eight finalists, a source said yesterday.

Within Metro, rail manager Fady P. Bassily was a candidate. Two black candidates also discussed the job with the board, sources said. They are Franklin White, New York's transportation commissioner, and William S. Norman, an Amtrak executive vice president.

Mortimer L. Downey, executive director of the New York authority, also was interviewed, sources said.

Gunn received undergraduate and graduate degrees from Harvard University and served as a Navy officer for three years. He worked at the Santa Fe, New York Central and Illinois Central railroad companies. In 1974, Gunn joined the Massachusetts Bay Transportation Authority as director of commuter rail services. He eventually headed all bus, trolley and train services there.

Before taking the New York job, Gunn headed the Philadelphia system from 1979 until 1984. He brought to New York several top managers from Philadelphia.