MADRID — Spain’s top-rated private station Antena 3 has taken a 15% stake in Spanish digital platform CanalSatelite Digital (CSD).The platform now is owned 85% by Sogecable, a joint venture of Canal Plus in France and Spanish conglom Prisa, and launches today. The new partnership means that CSD also will include the Discovery Channel, which already formed part of An-tena 3′s five-channel digital bouquet, Cable Antena, launched a year ago. The move, which ties up all Spanish digital pay TV soccer rights with CSD, comes as the Spanish government studies measures to limit or even ban soccer on pay TV in Spain. Such a ban would strike at the heart of Sogeca-ble’s empire. Sogecable also owns terrestrial soccer/movie pay net Canal Plus Espana. Meanwhile, in a separate deal that underscores the extent of the company’s interests, Sogecable has formally inked a deal with Warner Bros. and Portuguese media giant Lusomundo to jointly build 20 multiplexes in Spain. The exhibition pact was first announced at the Cannes film fest last year.