The American Guild of Musical Artists says the opera’s move to a smaller venue and a shorter schedule will mean less work for union members, who are usually guaranteed a certain number of work weeks per year. It filed a complaint on Thursday with the National Labor Relations Board saying the opera should have negotiated any move with the union.

“They have a legal obligation to bargain and give us all their information,” Gordon said. “They can’t just decide, `I’m going into business somewhere else, find me if you can.'”

The union represents about 200 workers at the opera, including about 50 choristers and 10 production workers.

The union’s complaint says the planned move will have the effect of “chilling the union and its members in the exercise of their rights.”

A spokeswoman for the company, Maggie McKeon, said Thursday the filing was without merit. Last week, general manager George Steel said the opera simply cannot afford to operate at Lincoln Center anymore.

City Opera has a reputation for mounting bold new productions and cultivating hot talents like Placido Domingo, Renee Fleming and Beverly Sills. But the company has struggled in recent years.

Its endowment has shrunk from $55 million to $9 million, audits obtained by The Associated Press show, and it has a projected deficit of $5 million this year.

It announced last week it was moving out of Lincoln Center, the landmark complex of concert halls that is also home to the Metropolitan Opera, the New York City Ballet, the Juilliard School of Music and other organizations.

The company also said it will do only three full-scale operas next season instead of five.