Eddie Hearn's Matchroom Boxing is to end its decade-long partnership with Sky Sports and migrate to DAZN.
Hearn has signed a five-year deal with the online streaming service, said to be worth a record nine-figure fee.
It means Matchroom's stable of fighters - which includes undisputed lightweight champion Katie Taylor - will only be viewable through DAZN.
Hearn signed a six-year deal with Sky Sports in 2015, to provide 120 nights of boxing to the British broadcaster.
The Athletic report that heavyweight champion Anthony Joshua and Dillian Whyte are not part of the DAZN deal.
The new contract comes into effect on July 1, meaning Taylor's May 1 clash with Natasha Jonas will be her last on Sky. That fight is on the undercard to Derek Chisora's heavyweight bout with Joseph Parker.
Hearn first linked up with DAZN in the United States in 2018, in a deal to broadcast 16 shows on American soil.
Speaking at the time he said, "It might take two or three years but what you'll find over time is that people will come off the traditional cable subscription and take individual packages.
"It's the future, without a shadow of a doubt. Kids aren't watching TV anymore."