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

Don King Sued in Contract Dispute: Boxing promoter Don King and Don King Productions Inc. were sued by a business associate, Mitchell J. Joseph, and MJM Entertainment Co. on grounds that King backed out of a commitment to put up collateral for three ventures, two of them pertaining to the 1992 Olympic Games in Barcelona, Spain. The federal lawsuit accused King of failing to honor a contract signed in November of 1989 that called for him to provide Joseph with an $80-million line of credit as part of an effort to merchandise the Olympic logo and mascot. The promoter also was accused of failing to put up $7.2 million for another joint venture with Joseph involving the leasing of Barcelona luxury homes to visitors during the Olympic games. (Suit Filed Sept. 10, 1990. Case No. 90-4853).