A selected summary of Southern California-related business litigation developments during the past week.

Movie Firms Sue Cruise Line: Nine movie companies filed a copyright infringement suit against Princess Cruises Inc., contending that the cruise line showed dozens of films aboard its ships without their approval. The federal suit said the cruise line is unlawfully showing movies in theaters and on closed-circuit television aboard the Dawn Princess, Sky Princess and Star Princess. The suit was filed by Columbia Pictures Industries, MGM-Pathe Communications, Orion Pictures, Paramount Pictures, Tri-Star Pictures, Twentieth Century Fox Film Corp., Universal City Studios, Walt Disney Co. and Warner Bros. It seeks to stop the unauthorized movie showings and asks unspecified damages. (Case No. 91-0292. Filed Jan. 17).