LOS ANGELES - At first glance, things might look familiar when representatives from both major actors unions sit at the negotiating table Tuesday with the studio executives.

But looks can be deceiving.

Two staff members from the American Federation of Television and Radio Artists will only be observers as the Screen Actors Guild begins negotiating a new contract.

In a letter Monday to SAG, AFTRA said it would not revisit its decision to sever the guilds' longtime unified negotiations.

The letter from Kim Roberts Hedgpeth, national executive director of AFTRA, was addressed to Doug Allen, her counterpart at SAG. A copy was obtained by The Associated Press.

A guild spokeswoman declined comment.

On Sunday, SAG's national board voted to let AFTRA join its negotiations with producers on a new contract for feature film and prime-time TV. SAG gave AFTRA, whose own talks with producers are set to begin April 28, until Wednesday to respond.

In its letter, AFTRA said it didn't appear there has been resolution of the "underlying problems" that prompted its national board to suspend the 27-year-old agreement under which the unions have bargained in tandem.

The AFTRA letter also called the 72-hour deadline set by SAG for a response a "pragmatically impossible timeline."

However, two AFTRA staffers will act as observers at the SAG talks, the letter said, in keeping with the guilds' mutual invitations.

"We extend our best wishes to the members of the Screen Actors Guild negotiating committee in their efforts to negotiate an excellent contract for performers," the letter concluded.

The split between the unions came last month as AFTRA accused SAG of trying to entice actors in the soap drama "The Bold and The Beautiful" to abandon the federation.

SAG President Alan Rosenberg rejected the allegation, calling it a "calculated" and "cynical" excuse by AFTRA to hasten the end of the partnership he claimed they had long wanted to end.