Members of the Screen Actors Guild (SAG) and the American Federation of Television and Radio Artists (AFTRA) voted overwhelmingly to join forces, officials from the two U.S. labor unions announced on Friday.

"The merger of SAG and AFTRA is approved," SAG President Ken Howard told a news conference, barely hiding his joy. The merger needed 60 percent of the vote to pass.

"This is the day we have decisively chosen a path of unity and strength. This is the culmination of years of work," he added.

Howard and AFTRA National President Roberta Reardon will serve as co-presidents of the combined union, to be called SAG-AFTRA. Both groups are headquartered in Los Angeles.

Reardon hailed the work of negotiators, describing it as "the culmination of two years of dedication, perseverance and lots of just plain hard work."

SAG, the largest labor union representing actors in the United States, has more than 125,000 members working in films, television programs, commercials, video games and online and new-media programming.

AFTRA has a membership of 70,000, including actors, broadcasters, singers, dancers, announcers, comedians, disc jockeys and other performers.

Eight-six percent of the 37,500 AFTRA ballots were submitted in favor of the merger, while 82 percent of the 55,000 SAG ballots were for it.

Talks about a possible marriage between the two groups began in 2003. Formal negotiations were only launched last summer.

According to negotiators, a proposed merger agreement was reached in January and later approved by the boards of both unions.

Proponents of the merger, which took effect immediately, claimed that the combined union will strengthen their bargaining leverage with studios and other media companies.

But, those who oppose it feared that the merger will bring negative impact on members' pension and health benefits.

More than 60 SAG members including Martin Sheen, Ed Asner and Valerie Harper filed a lawsuit in federal court to block the proposed merger, claiming the union failed to conduct an in-depth study of the effects the consolidation would have on SAG members' pension and health benefits.

On Wednesday, however, the opponents were dealt with a devastating blow, as U.S. District Judge James Otero rejected the challenge, declining to issue an injunction halting the union balloting.

Otero said that there was insufficient evidence that SAG had violated labor laws.

"Voting in favor of merger may or may not be in the best interest of the majority of union members," he said. "But the decision, for better or worse, belongs to the members, not to plaintiffs and certainly not to the court."