The seventh negotiating session between representatives of the Screen Actors Guild (SAG) and the Alliance of Motion Picture and Television Producers (AMPTP) was held Monday in an attempt to avoid a repeat of the 100-day writers strike which crippled production.

The two sides earlier had met 18 times from April 15 through May 6 without reaching an agreement. They are scheduled to meet again Tuesday.

Dozens of SAG members held a two-hour "Solidarity Rally" in support of their negotiation team Monday morning at its Los Angeles headquarters.

Saying that he remains optimistic that a deal can be reached, SAG President Alan Rosenberg encouraged members of the guild's sister union -- the American Federation of Television and Radio Artists (AFTRA) -- to hold off on ratifying the proposed contract that the group reached with AMPTP last month.

"We have 44,000 SAG members who are also AFTRA members. And we didn't give the approval to this deal. And yes, it does hurt our (bargaining) leverage," he told local television channel NBC4.

Rosenberg noted that differences in the SAG and AFTRA contracts could jeopardize actors' ability to obtain work.

According to a letter from Rosenberg posted on SAG's website, the main outstanding issues include increasing compensation for "middle class actors," continuing to give actors the right to consent to the use of clips, and paying residuals for new-media productions, such as those intended to be distributed via the Internet or cell phones.

"Our negotiating committee is working very hard in an effort to secure a fair contract for SAG members for television programs, motion pictures and new media formats," Rosenberg wrote.

When AMPTP, which represents major movie studios and television networks, announced an agreement with AFTRA, the smaller of Hollywood's two performers' unions, it issued a statement expressing its hope to reach an agreement with the 120,000-member SAG "that will prevent another harmful and unnecessary strike."