Los Angeles Opera said that Mr. Domingo, who cooperated and sat for an interview with the investigators, had “denied all allegations of unwanted contact and maintained that all his interactions were consensual.” The report added, without elaborating, that investigators “often found him to be sincere in his denials but found some of them to be less credible or lacking in awareness.”

Mr. Domingo did not publicly respond to the findings by Tuesday evening.

Last summer several women told The Associated Press, which first reported the allegations against Mr. Domingo, that they believed their careers had been harmed when they rebuffed his unwanted advances, which included “touching, persistent requests for private get-togethers, late-night phone calls and sudden attempts to kiss them on the lips.” It reported that one mezzo-soprano at Los Angeles Opera, who was not named, said that Mr. Domingo had pursued her so aggressively that she got panic attacks. She eventually had sex with him, The A.P. reported, but then cut off physical contact — a move she believed had derailed her career.

Los Angeles Opera, however, said its investigation had “found no evidence that Mr. Domingo ever engaged in a quid pro quo or retaliated against any woman by not casting or otherwise hiring her at L.A. Opera, especially since casting and other hiring decisions are complex, performance-specific and determined by multiple people.”

Debra Katz, an attorney who represents several women who have accused Mr. Domingo of sexual harassment, said she was disappointed with the finding that there had been no quid pro quo or retaliation. She said that one of her clients, a singer named Angela Turner Wilson, said that while Mr. Domingo was making advances to her in Washington (where they appeared in an opera together in 1999), he repeatedly suggested that she would be perfect for roles in Los Angeles.

That all changed once Ms. Turner rejected him, Ms. Katz said: “All those opportunities dried up.”

It was not immediately clear how European companies would respond to Los Angeles’s findings. Shortly before they were released, the Hamburg State Opera announced that Mr. Domingo had withdrawn from his coming performances there later this month, citing his concerns about the coronavirus, which has already shut down opera performances in several parts of Europe.