NEW YORK — James Levine will have a kidney removed in surgery this week, causing the conductor to miss the remainder of the Boston Symphony Orchestra's Tanglewood season.

The 65-year-old music director of both the BSO and the Metropolitan Opera will need six weeks of recovery time, the BSO said in a statement Tuesday. He is expected to be back on the podium for the start of the Met and BSO seasons in September.

Levine's kidney is being removed because of a cyst that is causing pressure and discomfort. No other treatment will be necessary, the BSO said.

"It is extremely frustrating that I need to have this surgery now," Levine said in a statement. "My projects at Tanglewood have been planned so carefully and coordinated in such detail by the festival administration. I especially regret not being here with Elliott Carter for his 100th birthday celebration, which I was looking forward to more than I can say."

Levine conducted the BSO in the opening of its Tanglewood season last weekend in a concert performance of Berlioz's "Les Troyens."

He is due back at the Met to conduct a pre-opening performance of Verdi's Requiem on Sept. 18 to mark Luciano Pavarotti's death last September. He opens the Met season on Sept. 22 and the BSO season two days later.

Levine, who conducts while seated on a chair, has had some health problems in recent years. He has sciatica, and in March 2006 he tore his right rotator cuff when he tripped and fell on the stage of Boston's Symphony Hall during ovations that followed a performance.

After the operation, which kept him from performances for four months, Levine lost a significant amount of weight.

He has been music director of the BSO since 2004 and music or artistic director of the Met since 1976. He made his Met debut in 1971.