 In December 1988, Cablevision announced that it would form a joint venture with NBC to operate the cable networks owned by the respective companies, including SportsChannel.Through this partnership, SportsChannel acquired the cable television rights to the National Hockey League, which aired several games involving non-New York area teams on the SportsChannel regional networks at times when no games involving local teams were set to air and served as the programming cornerstone for national sister network SportsChannel America upon its launch in 1990.SportsChannel New York lost the broadcast rights to the Yankees to the MSG Network, then its main competitor, after the 1988 season.