San Francisco -- OpenTV, a San Francisco-based developer of interactive TV software and services, said that Switzerland-based Kudelski Group, a developer of digital TV content protection technologies, has acquired voting control of the company from John Malone's Liberty Media in a stock deal valued at $132.3 million. As part of the deal, Liberty will pay OpenTV up to $19.7 million. Kudelski Group's companies include digital TV security software developer Nagravision, as well as Abilis, Quative, SmarDTV and SkiData. The company had previously worked with OpenTV to develop various digital TV services. OpenTV's software is used to power over 73 million digital TV set-top boxes deployed in 96 countries. Upon closing of the transaction, Kudelski will appoint Alan Guggenheim, currently the CEO of NagraStar -- a joint venture between Kudelski and EchoStar Communications -- as the CEO of OpenTV. The company will continue to operate independently and maintain its listing on the Nasdaq.