NEW YORK >> The Metropolitan Opera fired James Levine today, ending its association with a conductor who defined the company for more than four decades after an investigation found what the Met called credible evidence that Levine had engaged in “sexually abusive and harassing conduct.”

The investigation, which the Met opened in December after a report in the New York Times, found evidence of abuse and harassment “both before and during the period” when Levine worked at the Met, the company said in a statement. The Met did not release the specific findings of its investigation, which it said had included interviews with 70 people.

The statement also said that the investigation had “uncovered credible evidence that Mr. Levine engaged in sexually abusive and harassing conduct toward vulnerable artists in the early stages of their careers, over whom Mr. Levine had authority,” adding that he was also being fired as the artistic director of the Met’s young artists program.

“In light of these findings,” the statement continued, “the Met concludes that it would be inappropriate and impossible for Mr. Levine to continue to work at the Met.”

Levine, 74, has become the highest-profile figure in classical music to have his career upended during the national reckoning over sexual misconduct. It was an extraordinary fall from grace for a legendary maestro, a man many have considered the greatest American conductor since Leonard Bernstein.

He made the Met’s orchestra into one of the finest in the world, led the Boston Symphony Orchestra and the Munich Philharmonic and gained worldwide renown through recordings, telecasts and videos. His fame transcended classical music He shared the screen with Mickey Mouse in Disney’s “Fantasia 2000,” and made the cover of Time magazine in 1983, under a headline proclaiming him “America’s Top Maestro.”

Even before the accusations, the Met had been moving toward a post-Levine era. After years of ill health, he stepped down as music director two seasons ago. The company announced last month that Levine’s successor, Yannick Nézet-Séguin, would take on his new role next season, two years ahead of schedule.

But his termination has dealt the Met a serious blow at a moment of vulnerability. The company, the largest performing arts organization in the nation, costs close to $300 million a year to run, making it highly reliant on the generosity of donors — a dependence that has only grown as it has faced a box-office slump. Now the Met finds itself forced to court both philanthropists and audiences as it faces difficult questions about what it knew, or should have known, about its star conductor.

The Met suspended Levine and opened its investigation in December after the Times reported on-the-record accusations of four men who said that Levine had sexually abused them decades ago, when they were teenagers or his students. Levine called the accusations “unfounded,” saying in a statement that “I have not lived my life as an oppressor or an aggressor.”

But some questions arose early on about how the company had handled the case, including the fact that it began its investigation more than a year after Peter Gelb, its general manager, was first told that police in Illinois were investigating an accusation that Levine had sexually abused a teenage boy there in the 1980s.

The Met said that its investigation, which was led by Robert J. Cleary, a partner at the Proskauer Rose law firm who was previously a U.S. attorney in New Jersey and Illinois, had determined that “any claims or rumors that members of the Met’s management or its board of directors engaged in a cover-up of information relating to these issues are completely unsubstantiated.”

The accusations against Levine reported in the Times went back decades, and shared marked similarities.

Chris Brown said that Levine had abused him in the summer of 1968, when he was a 17-year-old student at the Meadow Brook School of Music in Michigan and Levine led the school’s orchestral institute. Brown, who went on to play principal bass in the St. Paul Chamber Orchestra, said that one night in the dorms, Levine had masturbated him and asked him to reciprocate — and then punished Brown when he declined to do so again, ignoring him for the rest of the summer, even when he was conducting him.

James Lestock, a cellist, said that he, too, was abused that summer when he was a student, and said that the abuse continued in Cleveland, where a tight-knit clique of musicians followed Levine, who was then an assistant conductor at the Cleveland Orchestra on the cusp of a major career. He said that at one point Levine had the group don blindfolds and masturbate partners they could not see. (Another participant confirmed this in an interview.)

Albin Ifsich, who went on to have a long career as a violinist in the New Jersey Symphony Orchestra, said that he had been abused by Levine for several years, beginning at Meadow Brook and continuing after he joined the group of young musicians who followed Levine to Cleveland and later New York.

Ashok Pai said he had been abused by Levine for years, beginning in 1986 near the Ravinia Festival in Illinois, when he was 16. Pai grew up near the festival, where Levine was music director, and wanted to become a conductor. Three decades later — after, Pai said, therapy had helped him realize how destructive those encounters had been — he detailed his accusations in the fall of 2016 to the Lake Forest Police Department in Illinois. Law enforcement officials said last year that they would not bring criminal charges against Levine, noting that while the state’s age of consent is now 17 — and 18 in some cases — it was still 16 in 1986.