James Levine, the Metropolitan Opera's music director for 40 years, has withdrawn from conducting to the end of the 2012-13 season to recuperate from a spinal injury, the opera house said on Friday.
He missed the first half of this season following emergency surgery after a fall on vacation last August.
"While this is a blow to Jim, our company, and his many fans, we want to make it possible for him to eventually return to the Met," Peter Gelb, the Met's general manager, said in a statement.
"The extended time off will give him the opportunity to recover fully, while also providing the Met with the chance to offer the best replacement conductors for next season."
The Met's 2012-13 season and casting will be announced in February.
The Met said it expected Levine to gradually resume his other duties as musical director including coaching and planning, and artistic leadership of the Lindemann Young Artist Development Program.
Levine said in a statement that he had discussed his decision with Gelb and other members of the Met.
"We have come to the conclusion that it would be profoundly unfair to the public and the Met company to announce a conducting schedule for me that may have to be altered at a later date," Levine said.
"As my condition improves, I feel confident I will be ready to conduct again soon, but I cannot risk a premature announcement."
Principal Conductor Fabio Luisi, who has already substituted for Levine this season, will conduct the cycles of Wagner's Der Ring des Nibelungen this coming April and May.
Levine has been at a rehabilitation facility since September.