In a striking development likely to surprise the art world, the Metropolitan Museum of Art is in discussions to turn over the Met Breuer to the Frick Collection. By off loading the last three years of its eight-year lease in the Madison Avenue building, the Met could free itself of an $18 million annual financial burden and focus on improving its Fifth Avenue galleries for modern and contemporary art. And the Frick could satisfy a need for temporary space while its Gilded Age mansion undergoes renovation.

Critics of the original deal will no doubt see the arrangement — announced jointly on Friday by the Met and the Frick — as confirmation that the Met Breuer was a bad idea to begin with, particularly since opening the Madison Avenue location forced the museum to divide its resources at a time of financial distress and to invest heavily in upgrading the building’s restaurant.

But the Met said the Frick venture, which would start in 2020, merely represents an evolution in planning, from using the Met Breuer as a temporary exhibition space for modern and contemporary art to expanding that type of programming in its Fifth Avenue flagship. “Our future is in the main building,” Daniel Weiss, the Met’s president and chief executive, said.

And while it may be hard to envision the Frick’s Rembrandts, Goyas and Renoirs in the Marcel Breuer-designed Brutalist building, Ian Wardropper, the Frick’s director, said the museum would use the Breuer as an opportunity to juxtapose its old master art collection with contemporary loans. “It gives us a chance to think ahead when it comes to reinstalling the collection,” he said.