Sir Ian McKellen has said openly gay US actors are prevented from having successful Hollywood careers.
Sir Ian McKellen picked up an award at the Berlin Film Festival
"It is very, very, very difficult for an American actor who wants a film career to be open about his sexuality," the gay British actor said.
"And even more difficult for a woman if she's lesbian. It's very distressing to me that that should be the case."
The Lord of the Rings star added: "The film industry is very old fashioned in California."
He was speaking at the Berlin Film Festival, where he received a lifetime achievement award.
Sir Ian, 66, said Oscar-nominated cowboy love story Brokeback Mountain may open the door to more films about homosexuality.
But the film industry was still reluctant to cast an openly gay man in a leading role, he said.
The same was not true on Broadway, where people were "very at ease with being open and honest".
His career in mainstream films "really took off once I'd come out and said I was gay", he said.
The actor, who came out in 1988, is one of the film world's most high-profile openly gay stars.
A number of other British actors such as Rupert Everett, Simon Callow and Sir Anthony Sher have publicly acknowledged their sexuality.
But fewer US actors have been willing come out and big names such as Rock Hudson and Montgomery Clift hid their sexuality for most of their lives.
While leading men may be discouraged from coming out of the closet, Hollywood has recently been praised by a gay rights group for making major films about gay characters.
Brokeback Mountain, Capote and Transamerica all feature prominently in the Oscar nominations.
"This has been a landmark year for lesbian, gay, bisexual and transgender-inclusive films," said Neil G Giuliano, president of the Gay and Lesbian Alliance Against Defamation.
"These are films with an emotional authenticity that have clearly connected with both gay and straight audiences alike.
"By telling our stories, this year's Oscar nominees have helped raise the visibility of lesbian, gay, bisexual and transgender issues and have given millions of Americans a greater understanding of who we are."