Brooklyn taketh, but sometimes Brooklyn giveth back.

Nancy Spector, the longtime chief curator of the Guggenheim Museum who made an unusual career move last spring to lead the curatorial team at the Brooklyn Museum, has decided to reverse course and go back to the Guggenheim as both chief curator and artistic director, a new and more powerful position created for her.

Richard Armstrong, the Guggenheim’s director, said that after the departure of Ms. Spector, a highly respected voice in contemporary art, the museum had put together a strong group of international candidates to replace her, “but for various reasons none of that really bore fruit, and as I came to a point of aggravation, I guess, Nancy and I saw each other and started a conversation.”

He said that as artistic director, Ms. Spector would have a greater say in programming and acquisitions not only at the Guggenheim in New York, but also at the museum’s satellites in Bilbao, Spain, and Venice, and an outpost being planned in Abu Dhabi. (Late last year, longstanding plans to build another satellite in Helsinki were voted down by Finnish lawmakers; besides giving the Guggenheim a presence there, the agreement to create the new museum would have added money to the Guggenheim’s endowment.)

“Because we’re multi-sited and that’s growing, it seemed to me like the institution really needed a discriminating synthesizer, and Nancy was interested in that and I think really the best person for it,” Mr. Armstrong said.