LOS ANGELES - Are U.S. television networks gay enough? Not yet, but ABC is getting close, according to a gay-rights group.

Michael Urie speaks during the Outfest Ugly Betty Panel at Directors Guild of America in Los Angeles, California, July 15, 2007. [Reuters]

The Gay and Lesbian Alliance Against Defamation (GLAAD) has given the Walt Disney Co.-owned network the highest marks of any of the five major broadcast networks in the group's first-ever report rating depictions of gay, lesbian and transgender characters and issues on prime-time TV.

The study assigned grades of "excellent," "good," "fair" or "failing" based on the number of "impressions," or occurrences, of gay characters, discussions or themes counted during 4,693 hours of programming examined from June 2006 through May 2007.

No network was rated as excellent. But ABC received a grade of "good" with 171 hours of gay-inclusive TV last season, accounting for 15 percent of its prime-time programming.

ABC shows also featured more regular characters who are gay, lesbian or transgender than any of its rival broadcasters, led by the first-season series, "Ugly Betty" and "Brothers & Sisters," according to the study, released on Monday.

The character of Betty's office cohort, Marc, played by Michael Urie, was depicted as coming out to his intolerant mother, while Alexis, played by Rebecca Romijn, was revealed to have once been Alex -- making her the first series regular transgender on a network comedy, GLAAD said.

"Overall, the approach that ABC takes ... can serve as a best-practice model," the study found.

GLAAD said networks and their advertisers stood to gain from more gay-friendly programming, as the gay community is generally more affluent, highly educated and brand-conscious than the population at large.

GLAAD noted that ABC, long known for its family-oriented, middle-of-the-road sitcom hits like "Happy Days," also has a history of landmark TV portraits of gay characters, dating back to 1977 and the debut of "Soap," which featured Billy Crystal as Jodie Dallas.

ABC also made broadcast history when Ellen DeGeneres' TV alter ego came out of the closet in 1997 on her sitcom "Ellen," becoming the first openly gay lead character on prime-time network television.

More recently, producers of the ABC hit medical drama "Grey's Anatomy" fired actor Isaiah Washington from the show in June after he reportedly made an anti-gay slur during a heated argument on the set with other cast members.

But GLAAD spokesman Damon Romine said ABC received no extra points for Washington's dismissal.

"This is all about representations on the screen," he said. "Our overall concern is increasing the inclusivity of the networks and having our lives be more visible."

The fledgling, youth-oriented CW network, formed from the merger of the now-defunct WB and UPN networks, scored the second-highest marks from GLAAD, rated as "fair" with 12 percent of its programming hours found to be gay-inclusive.

The CW reality contest show "America's Next Top Model" accounted for nearly all of that, the report said.

CBS, the nation's most watched network overall, and NBC also received grades of "fair," with 9 percent and 7 percent of their programming deemed gay-inclusive, respectively.

The study faulted CBS for casting gay and lesbian characters mostly as victims and villains in its procedural police dramas without including gays on any of the crime-solving teams.

"Since 'Will & Grace' left the air in May 2006, LGBT (lesbian, gay, bisexual, transgender) impressions on NBC have been few and far between," the report said.

News Corp.-owned Fox, the most watched network among young adult viewers most prized by advertisers, received GLAAD's lowest score, "failing," for including gay and lesbian impressions in just 6 percent of its programming.