A SAG-AFTRA study has found that, even as opportunities and conditions improve, discrimination persists against lesbian, gay, bisexual and transgender actors.

The survey, based on responses from over 5,600 union members, showed nearly half of lesbian and gay respondents and 27% of bisexual respondents “strongly agreed” that producers and studio execs believe that lesbian and gay performers are less marketable.

The report also found that over a third of LGBT performers, as well as some non-LGBT performers, had witnessed “disrespectful” treatment toward these minorities. And 16% of LGBT respondents reported they had experienced discrimination.

“Gay men were the most likely to report they have experienced some form of discrimination, with one in five reporting an experience,” the union said. “Bisexual actors were about half as likely to report discrimination as gay or lesbian actors.”

The report by SAG-AFTRA and UCLA’s The Williams Institute found one-third of survey respondents believed that casting directors, directors, and producers may be biased against LGBT performers. The survey, released Friday at the first-ever SAG-AFTRA convention, also showed over half of LGBT performers had heard anti-gay comments on set.

Respondents also said SAG-AFTRA members provide a supportive environment for LGBT performers. Additionally, many lesbian and gay respondents said they would encourage others to come out.

“We were pleased to see that our membership is overwhelmingly supportive of LGBT actors, and that many LGBT actors found benefits in coming out,” said Duncan Crabtree-Ireland, SAG-AFTRA’s Chief Administrative Officer and General Counsel. “Nonetheless, coming out remains a significant and consequential decision for many performers and we are committed to supporting our members in living honest and authentic personal and professional lives.”