Hollywood stars Ben Stiller and icon Jack Nicholson are taking on Tom Hanks as all the Hollywood stars pick sides in the battle between the two leading acting unions. Actors are threatening to have walkouts at the end of this month if talks between the unions and major film studios fail to resolve a dispute over pay and working conditions. Hanks recently signed an e-mail petition urging members of the American Federation of Television and Radio Artists (AFTRA) to accept a “solid deal” offered by studio heads. But fellow Hollywood actors Stiller and Nicholson are encouraging AFTRA members to turn down the proposal after siding with rival union, the Screen Actors Guild (SAG), whose members are negotiating a separate contract. Stiller and Nicholson are set to appear in print ads today that urge union members to reject the proposal – siding instead with SAG, which claims the contract would set a precedent that could potentially harm their negotiating power with movie studio bosses.The ad was signed by the pair and states: “We are not finished… We believe there are issues that are at the heart of every actor’s career that remain unresolved by AFTRA.” The current contract for both unions will expire on Monday. Among negotiating points for both unions are daily minimum compensation for actors and DVD and Internet fees. AFTRA bosses have warned that turning down their proposed deal with the studios could spark a strike similar to the The Writers Guild of America strike, which brought Hollywood to a standstill from November (07) until February (08), and cost the California economy a projected 37,700 jobs and $2.1 billion in lost output, according to reportstom-hanks