The move to merge Hollywood’s performer unions is getting another boost from pilot season.

Preliminary figures compiled Thursday show that producers of an overwhelming number of broadcast network TV pilots have opted to sign the American Federation of Television and Radio Artists rather than the Screen Actors Guild. AFTRA and SAG had no comment.

Among the more prominent of the 70 pilots that have gone to AFTRA: Fox’s “Alcatraz,” ABC’s “Charlie’s Angels,” “Once Upon a Time” and “Poe,” NBC’s “Playboy” and “Prime Suspect.”

It’s the third year in a row that AFTRA’s dominated pilot season — meaning that SAG’s longstanding hold on primetime work continues to erode, even though SAG’s elected leadership has become increasingly moderate and less confrontational.

Producers have shunned SAG on nearly all new primetime shows following SAG’s unsuccessful effort in 2008 to hold out for richer terms on its master feature-primetime contract for nearly a year.

Merger proponents at both unions assert that the split jurisdiction in primetime for shows shot on digital creates problems for working actors attempting to qualify for the separate SAG and AFTRA health and retirement plans. If the unions were merged, proponents believe it would become more feasible to combine the SAG and AFTRA health and pension plans — which are operated independently of the unions with union-industry boards overseeing each.SAG prexy Ken Howard and AFTRA president Roberta Reardon have engaged this year in a “listening tour” to sound out members on the specifics of a merger. Howard said at the SAG Awards on Jan. 30 that he wanted the two unions combined by the next SAG Awards.

Merger attempts in 1999 and 2003 were voted down by SAG members amid concerns about SAG losing its identity as an actors union and difficulties in merging the union-industry health and pension funds.

Merger proponents have contended that combining SAG and AFTRA would give actors more clout and improve operating efficiencies. Opponents have grown frustrated over what they perceive to be SAG’s lack of effort to sign primetime shows shot on digital and three members filed charges last year with the National Labor Relations Board, alleging that SAG’s inaction represented a violation of its duty to represent members. The NLRB turned down the charges and the trio is appealing that ruling.