Carmen E. Turner, general manager of the Metro transit system, will leave Metro to assume the No. 2 position at the Smithsonian Institution, Smithsonian Secretary Robert McC. Adams confirmed yesterday. Turner will leave Metro for the Smithsonian in mid-December, succeeding Dean Anderson, who was fired in July.

There was no indication yesterday who might replace Turner as general manager of the Washington Metropolitan Area Transit Authority, which transports about a million people a day and this year has an operating budget of $612 million. Metro Board Chairman Mary Margaret Whipple said a search committee will be established to find a successor for Turner, who has been general manager for seven years and whose decision to leave caught board members by surprise.

Turner joins the Smithsonian as chief operating officer at a moment of severe financial and managerial tension. Discontent has surfaced among the staff over Adams's management style, which has been perceived as erratic and disengaged from the daily workings of the institution.

Although committed to a number of expensive projects, including the National Museum of the American Indian, the institution is seriously short of funds. This summer Adams said he planned to make major budget cuts.

Sources within the Smithsonian said yesterday that the search committee that recommended Turner had been looking for an experienced manager capable of guiding the institution through a troubled period. Turner, 60, has been highly praised for her skill at running the transit system and lobbying on its behalf, and is known as a consummate bureaucrat.

"There's a part of me that will always be with Metro," Turner said yesterday, "but one of the wonderful things about life is having an opportunity for something new and different, and particularly where you can believe you can make a contribution."

Starting as a GS-2 clerk typist, she rose through the federal government to the position of acting director of civil rights at the Department of Transportation under then-Secretary William Coleman. In 1977 she moved to Metro as chief of administration.

There is no obvious inside candidate to replace Turner. Metro board members said they plan to consider outside candidates.

Turner's deputy, John S. Egbert, will retire at the end of the year.

Two assistant general managers, William A. Boleyn and John F. McElhenny, are approaching retirement age.

The two youngest senior officials at Metro are John F. Potts, assistant general manager for administration, and Fady P. Bassily, assistant general manager for rail. Both are 44.

During Turner's tenure, the emphasis at Metro moved beyond building the regional rail network to operating the system and dealing with problems, such as maintenance, that face all aging transit systems.

In the past seven years Metro has grown from 42 miles and 47 stations to 70 miles and 63 stations, including the two newest stops at Wheaton and Forest Glen on the Red Line in Montgomery County, which opened Sept. 22.

To complete the remaining 13.5 miles of the planned 103-mile system, Metro is asking Congress this year for an additional $2.1 billion. The Bush administration wants to reduce that share. Turner has been negotiating with the administration, regional officials and lawmakers.

"This is really going to be a loss for the region," said Rep. Frank R. Wolf (R-Va.). "It will be difficult to bring in a new person during these tight financial times."

Metro presented Turner with a number of challenges. Local and state governments that contribute money to Metro's operations are having trouble financially and the D.C. government has fallen behind in its payments. Fares probably will have to be raised next year, and the possibility exists that completion of the system will be further delayed.

Construction on segments of the Green Line, the system's only unopened line, is a year behind schedule, in part because of problems that consultants found with Metro's management of the construction and troubles with the construction company building the line.

Turner said these problems had nothing to do with her decision.

"If I were going to look for another job because Metro has challenges ahead in the next few years, I would have looked five years ago," she said. "Metro has challenges every day."

At the time of Anderson's firing, some Smithsonian officials speculated that Adams had acted rashly in an attempt to stem criticism of the institution's management, but regent David Acheson said the firing came about because of problems in the two men's "working relationship." Adams said then that an ongoing review of the Smithsonian's management structure had convinced him that "probably some substantial changes" were necessary.

Turner described her upcoming job as part of "Bob Adams's new management team," and said, "I suspect the secretary is looking at some management changes. I'm not totally familiar with all of those, but I'm sure once I join the staff I will be an integral part of that process."

In a statement released from a Massachusetts airport, Adams said Turner's "long and outstanding career as an administrator and in public service gives her special insights and abilities for managing a complex organization like the Smithsonian."

Told of the selection of Turner, National Museum of American History Director Roger Kennedy said, "That would be wonderful. She's got a terrific reputation for getting things done, for real political savvy and a great breadth of interests beyond those conventional to a person who has grown up as an administrator."

Adams has also been under pressure for several years from within the Smithsonian and on Capitol Hill to hire more blacks and other minorities. Peggy Cooper Cafritz, an arts activist and chairman of the Smithsonian Cultural Education Committee, said the choice of Turner shows that "Adams has been listening. As far as hiring a black in the number two position, it's a huge move for him. So far he has been giving messages to his bureau directors and assistant secretaries. He's finally given them a concrete example of a very large proportion."

Yesterday there was also news of another change at the Smithsonian. Treasurer and chief fiscal officer Ann R. Leven resigned Monday to accept a newly created job as deputy treasurer of the National Gallery of Art.