Sky and BT have announced a deal that will allow the rival broadcasters to sell their channels on each others' platforms.
Under the terms of the agreement, BT will wholesale its BT Sport channels to Sky, allowing the firm to sell them directly to Sky satellite customers.
This will mean BT's live UEFA Champions League and Premier League football being made available on the Sky platform.
BT has spent north of £3.5 billion on Champions League and Premier League football rights since 2012 in a bid to compete with Sky.
The deal between the two giants will also see BT "market and sell" Sky's Now TV service to its customers.
Now TV offers Sky's most popular content, including Sky Sports, Sky Cinema and the Sky Atlantic channel.
Gavin Patterson, chief executive of BT, said: "This is an important day for BT and for our customers, who will be able to enjoy a whole range of Sky's sport and entertainment programming on their BT TV boxes.
"This is the next logical step for our TV and content strategy. We feel that now is the right time to broaden the ways in which we distribute BT Sport.
The new services will be available to customers from early 2019.
Sky boss Jeremy Darroch said: "This is great news for Sky customers who will be able to access all matches on Sky and BT channels from the Premier League, UEFA Champions League and Europa League directly with a single Sky TV subscription and with the great customer service that we provide."