BT Sport has paid £1.18 billion ($1.45 billion, 1.36 billion euros) to retain exclusive rights to show Champions League and Europa League games in the United Kingdom, the broadcaster announced on Monday.
The new contract, valid from 2018 to 2021, is worth £394 million per year, a significant increase on its current £299-million-per-year deal.
BT, formerly known as British Telecom, has shown Champions League games since 2015, having outbid free-to-air broadcaster ITV and subscription rival Sky in a 2013 auction.
"We are delighted to have renewed these rights," said BT consumer chief executive John Petter in a press release.
"The UEFA Champions League and UEFA Europa League are two of the best competitions in the world and we would like to thank (European governing body) UEFA for choosing us as their exclusive broadcast partner in the UK."
According to media consultants Enders Analysis, BT attracted an average of 512,000 viewers to its subscription service for Champions League games in 2015-16, an improvement on Sky's equivalent figure of 479,000 the previous season.
But the 13 matches shown free-to-air on BT in 2015-16 were watched by an average of just 150,000 viewers -- a huge fall from 3.8 million under ITV.
The new deal gives BT exclusivity across all live games for the first time, while Champions League 'double-header' nights will enable it to show back-to-back group-stage games.
BT will also make video clips, weekly highlights, UEFA's magazine show and both competitions' finals free to watch on social media.
Guy-Laurent Epstein, UEFA marketing director, said: "UEFA is delighted to have extended the relationship with BT Sport for a further three seasons, taking our partnership to 2021.
"BT Sport has proved to be an innovative broadcast partner, pushing the boundaries and covering the UEFA Champions League and UEFA Europa League in new ways.
"BT have delivered strong audiences in the UK and we are excited about their future plans for the use of social media, which will engage a growing fan base that consumes sport in different ways."