In more than a dozen years as president and chief executive of the Metropolitan Museum of Art, William H. Luers never really spoke out about the nation's biggest art museum or his tenure there. That was the deal he cut with the museum's director, Philippe de Montebello.
Mr. de Montebello, though technically his subordinate, rules over the Met's art, and has always aspired to hold both jobs one day, as most museum directors do. ''We agreed it was essential that he be the voice of the museum,'' Mr. Luers said.
On Jan. 31, Mr. Luers, a tall, tweedy former career diplomat, will be handing over the chief executive's post to Mr. de Montebello. On a recent day, sitting at the big round table in his office, he offered his thoughts as he prepared to depart for his new job as chairman and president of the United Nations Association of the U.S.A.
In a wide-ranging interview, Mr. Luers took credit for professionalizing the Met's staff and for being -- if not the public ''voice'' -- at least ''Mr. Outside'' to city and state administrators. He predicted that the museum would grow in importance if it tapped into new media like the Internet. And he recalled his fondest moment as the day that Met officials, courting Walter H. Annenberg, showed him a model of the galleries they had designed in hopes of gaining his huge trove of Impressionist paintings. By the look in Mr. Annenberg's eyes, Mr. Luers knew the museum had clinched his bequest of the works.
Mr. Luers said that the Met was bursting at its seams and working hard to expand bathrooms and other amenities for crowds that often reach 30,000 to 40,000 on Saturdays and Sundays. ''Whether there's an outside limit that says on a Sunday you can take only 50,000, I don't know,'' he said.
Ever the diplomat, Mr. Luers said his sharing of power with Mr. de Montebello, however strained their relationship sometimes was, served its purpose. ''I think it worked because the trustees wanted it to work,'' he said. Mr. Luers had only a mild warning for Mr. de Montebello, who is assuming the chief executive's post as well as remaining director, a job he has held for 21 years. ''There are a lot of very complicated management issues,'' Mr. Luers said. ''And he has 18 curatorial departments. It just places a tremendous strain on the director. But I think he will be fine.''
Putting his best spin on their relationship, Mr. Luers said, ''Inevitably, we had moments of disagreement because of our positions.'' He declined to discuss specifics but characterized them as things like the pace of upgrading administrative systems and computerization.
''But we worked it out, and I think he's comfortable with the pace now and he's behind it,'' Mr. Luers said. ''There have also been some disagreements about individual people who would be hired. But these were momentary differences.''
On some occasions, he said, when the two disagreed, they relied on other executives at museum.''When they saw us talk about an issue, they made sure we faced issues together,'' he said.
Mr. de Montebello, noting that ''identical twins and married couples have moments of disagreement, too,'' also played down their differences. ''We have become a very large museum with a big budget, and he has put a structure in place and a staff and an overall administrative complex that runs very smoothly,'' Mr. de Montebello said.
The Met has a $116.5 million annual budget and 1,800 full-time employees.
Mr. Luers had agreed to retire when he turned 70 this year, on May 15. He accelerated his departure after he was asked o to lead the United Nations Association, which does research and organizes chapters of United Nations supporters.
Museum trustees and other Met-watchers agree with Mr. Luers's assessment of his contributions and add another: his nonstop entertaining of donors, potential donors, well-placed politicians and other powers that might be able to help the Met. Much of that took place at the Met-owned apartment he occupies with his wife, Wendy.
''He's indefatigable,'' said Carl Spielvogel, a trustee. ''I don't know many people willing to be out at breakfast, lunch and dinner seven days a week, but he was. And he was very good at it.''
No one expects Mr. de Montebello, who is far less outgoing, to pick up that particular mantle (although Mr. Spielvogel, who used to head the museum's business committee, said, ''Philippe said to me at one point, 'Carl, any place you want me to go to raise money, I will go.' ''). Rather, many Met social activities are likely to revert to its development office, headed by Emily K. Rafferty.
The Met is now returning to a management structure employed by most museums. ''The flaw in splitting the job is that nothing is clearly an artistic decision -- it's always a combination of artistic and economic issues,'' said Richard E. Oldenburg, a former Museum of Modern Art director who is now chairman of Sotheby's North America.
In leaving, Mr. Luers will have to give up that fancy apartment, but he said he would most miss working at the Met and being able to roam the galleries when they are closed to the public. ''There's nothing like this place,'' he said.
Mr. Luers said he had come to the job with a longstanding love particularly of the Old Masters and 19th- century European art. He leaves with broader taste, especially a new appreciation for ancient art.
''Every exhibition here opened my eyes to ancient civilizations,'' he said. ''There are commmon fundamental ideas, and the one thing I've thought of is that I would create a curator of the whole, a department of curators who would spend their time relating the collections to each other. It is fascinating to me how much we can learn from juxtapositions of the way different civilizations have dealt with the same subjects.''
On Tuesday, the Met will hold a dinner honoring Mr. Luers, along with Arthur Ochs Sulzberger, the museum's outgoing board chairman and the chairman emeritus of The New York Times Company; James R. Houghton, the incoming chairman, and David E. McKinney, a former I.B.M. executive who is becoming the chief operating officer, with the title of president, reporting to Mr. de Montebello.
In his new position at the United Nations organization beginning on Feb. 1, Mr. Luers returns to his first love, international affairs. It seems revealing that in a recent speech at Hamilton College, his alma mater, he cited as the highlights of his Met career the visits of Vaclav Havel, Andrei K. Sakharov and the Emperor and Empress of Japan.
Showing a trace of emotion in his voice and invoking a custom of the Foreign Service, Mr. Luers said he would return to the Met often to see its displays, but not to attend its parties. ''You don't return,'' he said.
Correction: January 8, 1999. An article yesterday about William H. Luers, the departing president of the Metropolitan Museum of Art, misstated the relationship between his position and that of Philippe de Montebello, the museum's director. The two have been equal, both reporting to the chairman; the director is not subordinate to the president. As the article noted, Mr. de Montebello will assume the additional title of chief executive on Jan. 31.