Acquavella Galleries has brought on an unlikely new director: Philippe de Montebello, the longest-serving former head of New York’s Metropolitan Museum of Art. The art historian’s hire, announced today, is effective immediately.

In his new role, the former museum executive will focus on curating special exhibitions and developing publications. He won’t be directly involved in sales.

Since stepping down from the Met in 2008, the 81-year-old has technically been in semi-retirement, but he has maintained an active role in the art world in New York and Europe. In 2015, he became chairman of the Hispanic Society of America, where he has overseen a $16 million renovation of its New York building, an expansion of the board, and ambitious international loan shows. He also serves as a professor at New York University’s Institute of Fine Arts and as a trustee of Madrid’s Prado Museum. De Montebello will continue to fulfill all three roles after he begins at Acquavella.

“I have deeply admired his career for the past 50 years, and will now have the privilege of discussing works of art and projects with him,” Bill Acquavella said in a statement. “He will be an enormous asset to the gallery and our clients.”

The tireless de Montebello remarked in a statement: “I have enjoyed taking on new challenges since leaving the Met, and welcome this opportunity to advise the gallery and bring new ideas to light.” He noted that the appointment formalizes a decades-long friendship and professional relationship with the Acquavella family. De Montebello told the New York Times, which first reported the story, that he had been in talks with the gallery over the past few years about how they might work together.

News of de Montebello’s hire is the latest in a stream of increasingly high-profile museum veterans joining the commercial sector. Last month, Julia Peyton-Jones, the former director of London’s Serpentine Galleries, announced she would join Galerie Thaddaeus Ropac as senior global director. Arnold Lehman, the former director of the Brooklyn Museum, and John Elderfield, the former chief painting and sculpture curator at New York’s Museum of Modern Art, have also made the jump to advise the private sector.