BT Sport has won the exclusive rights to show the European Rugby Champions Cup and Challenge Cup from the 2018-19 season to the end of 2021-22.
Up to 134 matches a season will be shown live on TV in the UK and Ireland over nine weekends.
Live streams will also be available on the firm’s app and website.
BT Sport also has the rights to the Aviva Premiership and the Anglo-Welsh Cup, It will show up to 69 live premiership matches this season.
The new European deal will kick in after the forthcoming season, the last of the current deal which has seen both BT Sport and Sky Sports sharing the rights to broadcast the competitions.
Vincent Gaillard, chief executive of European Professional Club Rugby, welcomed the news.
“We are delighted to move to a single pay-TV platform for European club rugby with a premium broadcaster in BT Sport, who share our commitment to the promotion of our competitions,” he said.
“The interest that we have seen through the tender process shows how the tournaments continue to go from strength-to-strength.”
As well as its rights to rugby union coverage, BT Sport holds live UK TV rights to 42 Premier League football matches per season, as well as exclusive rights to the Uefa Champions League and several other football competitions.