Philippe de Montebello, who has achieved the status of longest-serving director of the Metropolitan Museum of Art in New York City, will retire by the end of this year after three decades on the job.

Philippe de Montebello, 71, announced Tuesday that he plans to retire. He will remain director of the Metropolitan Museum of Art until Dec. 31 or until a successor is found, the museum said.

De Montebello became director of the famed museum in 1977 and says leaving the institution is not easy for him.

He made the announcement of his withdrawal Tuesday, Dec. 8, at the museum trustees' January board meeting, the Associated Press reports. He planned to make a formal announcement Wednesday.

“Difficult as it is to contemplate life away from an institution to which I have devoted all but a few seasons of my professional life, I know the time is right for both my own, and the museum's, inevitable transition,” de Montebello said in a statement issued by the museum.

The world-renowned museum will begin preparations for this “transition” by forming a search committee with the mission of finding a replacement for de Montebello.

James R. Houghton, chairman of the museum's board of trustees, said in a statement that to call the announcement the end of an era “surely constitutes one of the great understatements, not only in the museum's life, but in the cultural life of the city, the state, the nation and the world,” as quoted by the AP.

“He leaves an incomparable legacy,” Houghton said. “No museum director anywhere has done more to expand and enrich the appreciation of art for more generations and with greater taste, erudition, diplomacy and vision.”

De Montebello, born in Paris in an aristocratic family, is the eighth and longest-serving director of the Met. He moved to the United States with his family in the early 1950s and became a U.S. citizen a few years later.

He studied art history at Harvard University and graduated magna cum laude.

He first joined the Met in 1963 as a curatorial assistant in the department of European paintings. He left New York for four years, between 1969 and 1974, during which time he served as director of the Museum of Fine Arts in Houston, and then returned.

He was named director of the Met in 1977 and subsequently made a name for himself as one of best leaders in the institution’s history. He is credited with having expanded the 138-year-old Manhattan museum, nearly doubling its physical size, increasing gallery space and acquiring marvelous collections.

Last year, de Montebello received France's most prestigious award, the Legion of Honor medal, with France's culture minister calling him one of New York's “most eminent cultural figures.”