A referendum to merge the industry’s two performers unions will be delayed at least until the fall because a report on melding the guilds’ two pension and health plans has yet to be completed.A merger of the Screen Actors Guild and the American Federation of Television and Radio Artists has to be put to a referendum vote of the membership. But before that, each union must decide whether to put a merger to a referendum. And they are reluctant to do so until major questions have been resolved. Trustees of the guilds’ two pension and health plans — who include reps both for producers and the unions — still have not received reports that define how the new benefits structure will be set up. There have been delays in completing actuarial studies. A vote was to be taken this weekend at the SAG plenary meeting on whether to send out a referendum. That vote has now been delayed, perhaps until the next SAG plenary in the late fall. And the pension and health report also is not expected to be ready in time for AFTRA’s annual convention, which starts on July 31. “We’re not counting on it,” said AFTRA president Shelby Scott. Although both unions could send a merger out without a guidebook of the new P&H plans, “We don’t want to send it out without it,” she said. There is now some question as to when AFTRA can delay such a vote, because its guidelines say that the annual convention has to decide whether such a referendum will go out. The merger’s delay also comes as opposition groups mount an effort to defeat the plan, although the boards of both unions have thus far overwhelmingly approved plans for unification. Both unions have long talked of a merger — even back to the 1950s — but this is the closest they have come to achieving that goal. The single organization would number about 120,000 members.