Turner Broadcasting successfully bought the broadcast rights to the Champions League and Europa League beginning for the 18-19 season and will launch a stand-alone sports streaming service that will broadcast the vast majority of matches.

Many of the most important Champions League games, including the semifinals and final, will still be broadcast on cable television.

But eighty percent of matches will only be available to fans who pay for the new subscription service.

Turner, which owns cable networks including TNT, TBS, CNN and Cartoon Network, and already owns some rights for games in Major League Baseball, the N.B.A. and the men’s N.C.A.A. basketball tournament, will build its new product around soccer, at least to start.

Turner paid $60 million for the rights.

Turner president David Levy said viewers should not expect any games from the other sports for which it owns the rights, such as the N.B.A. or Major League Baseball, to appear on the streaming service, at least not at the beginning.

“This isn’t about taking current rights and putting them on this platform,” he said. “This is a new platform, which is untethered to our existing businesses.”

NBC created a similar service for the Premier League priced at $50 that puts about a third of the schedule in their streaming-only product.