The Motion Picture Assn. of America yesterday filed a copyright infringement suit against Cencom Cable Associates, claiming the St. Louis-based multisystem operator has underpaid by $ 3 million royalties owed to Hollywood programmers.“The MPAA will not stand by and let cable operators take advantage of copyright holders,” said MPAA topper Jack Valenti. “Cencom has grossly abused the system. We will do our best to make sure that Cencom … does not profit from its deception,” he said. Compulsory payment Under the mechanism known as the cable compulsory license, cable systems pay yearly fees to programmers for access to so-called “distant signals” shown on broadcast stations such as superstations WTBS, WOR and WGN. The fee paid by the cabler is based on a percentage of gross receipts received from the tiers of service that contain broadcast signals. MPAA’s suit alleges that Cencom established an unpublicized lower cable tier for $ 2.95 per month for the express purpose of avoiding copyright payments. The suit claims that only 1,000 of Cencom’s 108,000 cable customers in St. Louis subscribed to the $ 2.95 basic tier, but that Cencom “computed its gross receipts as if all subscribers took only the $ 2.95 tier.” MPAA collects $ 21 mil MPAA recently settled out of court a similar lawsuit filed in 1991 against Bresnan Communications. Terms of the settlement were not disclosed. However, MPAA earlier this year claimed it received a $ 500,000 out-of-court settlement from an undisclosed cable operator accused of a similar infraction. MPAA claims it has collected $ 21 million since 1986 by taking copyright enforcement action against cable operators. Cencom, which has 527,600 cable subscribers nationwide and is the 19 th-largest MSO, had no comment on the MPAA suit, according to a company spokeswoman.