Gemstar unit files patent lawsuit

Gemstar-TV Guide International Inc.'s TVG horse racing network sued track owner Magna Entertainment Corp. and two subsidiaries over patents for interactive betting.

Also sued were HRTV, which also runs a horse racing TV network, and the XpressBet Inc. wagering business. The suit, filed in federal court in L.A., claims that the companies infringe on two patents related to systems that let users bet on races by remote control through their TVs.

Magna is North America's biggest owner of horse tracks, including Pimlico in Maryland, where the Preakness, the second leg in racing's Triple Crown, will be run today. Both TVG and HRTV show horse racing and allow viewers in 11 states to bet through interactive TV, online or over the telephone.

Gemstar is based in Hollywood.