To understand why Hollywood is taking the threat of a strike by the Screen Actors Guild seriously, look no further than Alan Rosenberg's actions during solidarity march last November with striking screenwriters. Mr. Rosenberg, the president of the 120,000-member actors' union, made Patric M. Verrone, his counterpart at the West Coast writers' guild, look like a pacifist during the march down Hollywood Boulevard. While Mr. Verrone mostly smiled and waved, Mr. Rosenberg screamed, “On strike! Shut 'em down! Hollywood's a union town.” On Tuesday, as his turn at the bargaining table arrived, Mr. Rosenberg said he remained angry enough over performer compensation levels to bring the entertainment industry to a halt again. “Aside from my family, I have two great loves in my life: acting and the fight for social justice,” he said. “Oh yes, we are very serious.” Mr. Rosenberg, 56, and his negotiating team presented proposals for a new contract to the Alliance of Motion Picture and Television Producers, the organization that represents the interests of movie studios and networks. Among the gains SAG is seeking are increased payments for the distribution of television shows and movies on the Web and a bigger share of DVD revenue. The guild also wants actors to get a cut of product placement fees that come when the networks and studios weave advertising into their entertainments. The current three-year contract expires on June 30. Similar requests by the Writers Guild of America last fall - in particular the DVD demand - were greeted so coldly that screenwriters walked off their jobs. The strike shut down most television production, disrupted preparations for a handful of big-budget movies and caused $3.2 billion in damage to the Los Angeles economy, according to the Los Angeles County Economic Development Corporation. A spokesman for the producers' alliance declined to comment Tuesday. Both sides declined to specify proposals. Mr. Rosenberg, who is known for roles in “L.A. Law” and “Cybill,” has been preparing for his role as the center of the latest Hollywood labor skirmish for longer than many people in the entertainment business realize. The son of a swing-era musician, Mr. Rosenberg was a war protester in the 1960s, at one point joining the Black Panthers. He said he was spurred to become involved in organized labor in Hollywood after President Ronald Reagan's firing of striking air traffic controllers in 1981. He first ran for a position on SAG's national board earlier this decade, and was elected president of the guild in 2005, narrowly defeating a more moderate candidate, the actress Morgan Fairchild. Some in Hollywood say Mr. Rosenberg's move into the role of confrontational guild leader comes less from politics than from personal psychology. His older brother, Mark Rosenberg, was a noted civil rights activist who became president of Warner Brothers before dying of heart failure in 1992 at the age of 44. Leading SAG in its battle to secure a ground-breaking labor contract allows Mr. Rosenberg to continue his brother's work. “There's no doubt that he cared deeply about content creators, and that I share that with him,” Mr. Rosenberg said. While not rich by Hollywood standards, Mr. Rosenberg is not exactly what most people consider middle class, either. He is married to Marg Helgenberger, a millionaire because of her lead role on the CBS drama “CSI: Crime Scene Investigation.” As negotiations get under way, Mr. Rosenberg and his lieutenants are facing hurdles. The producers' alliance has made it clear that it intends to use the newly negotiated contracts with writers and directors as a blueprint for the actors, while Mr. Rosenberg said he found both those pacts unsatisfactory. The producers also arrive on this battlefield with tested artillery, perhaps the most important being an aggressive public relations apparatus that has tried to learn from its missteps during the writers' strike. SAG is waging its campaign as the industry is still recovering from the writers' strike. “The wounds on both sides are still very raw,” said Daniel H. Black of the Greenberg Traurig law firm, which has a large entertainment practice. “There's no way that doesn't factor in here.” Mr. Rosenberg's union also has a history of infighting that has derailed its plans in the past. Unlike traditional labor unions, where workers are generally bound by economics, there are groups within SAG that have little in common with each other. According to some estimates, two-thirds of the union's members earn less than $1,000 a year acting. On the other extreme are stars who routinely take home $20 million a movie in salary, plus millions more in perks. Some top-earning actors, among them George Clooney and Sally Field, have already pressured Mr. Rosenberg to walk a less-militant line. SAG has also clashed with the American Federation of Television and Radio Artists, which mostly represents a small number of television actors. The unions have typically negotiated contracts together, but the smaller organization this time has decided to go it alone, for various reasons. AFTRA, which rejected a last-minute appeal from SAG on Monday to join it at the bargaining table, is set to begin negotiations with the studios on April 28. Nonetheless, one important bit of timing is breaking SAG's way. During the last strike, the six media conglomerates that control the entertainment business were able to convince Wall Street that the picketing was immaterial to their bottom lines. Many held up positive earnings reports during the walkout as evidence. But some damage is expected to pop up over the next month, when the media giants release their quarterly earnings. And SAG got a public relations gem handed to it last week from CBS: the company reported that it rewarded its chief executive, Leslie Moonves, with a $36.8 million paycheck in 2007, up from $28.6 million in 2006. Disclosures like that are hard to swallow for SAG, which has been repeatedly told by the entertainment conglomerates that they cannot afford heftier payments for talent. “This is not about wealthy actors trying to get wealthier,” Mr. Rosenberg said. “All we want is to be compensated fairly.” - NYT __