The combined business will bring together rights to sports including the Premier League, the Champions League and the Olympics, which is worth as much as £633m (£773m) to the telecoms operator.
But what does the shake-up when it comes to coverage of some of the biggest events in world sport?
What has been announced?
BT announced on Thursday that it has finalised a deal to create a major UK sports broadcaster with Warner Bros Discovery that will see the companies form a 50-50 tie-up, bringing together BT Sport and Eurosport.
While the two brands will initially stay separate they will ultimately be brought "together under a single brand in the future".
Under the terms, the FTSE 100 (^FTSE) firm said it will immediately receive £93m in instalments over three years from Warner Bros Discovery, and up to £540m if future conditions are met over a period of four years. This could be paid out sooner if either the £540m performance cap is hit, or WBD trigger a call option to take full control.
"We have finalised the sports joint venture with Warner Bros Discovery to improve our content offering to customers, aligning our business with a new global content powerhouse," said Philip Jansen, CEO of BT.
The joint venture will also enter into a new agreement with telecoms provider Sky, which will run beyond 2030 to extend the availability of BT sport/Eurosport content on its platform.
The final name of the joint brand has yet to be unveiled and the deal is expected to be completed by the end of 2022.
What does this mean for BT subscribers?
The venture would see BT customers get access to Discovery's sport and entertainment content. For BT, this means its broadband and television customers, and for WBD its Discovery+ streaming service.
The deal would see combined sport content of BT Sport and Eurosport made available for to new and existing subscribers on BT and WBD's respective platforms and app.
Both customers who subscribe to BT Sport directly through BT as well as BT TV users will also gain access to Discovery+ as part of their existing subscriptions.
“We are excited to bring fans a new premium sport offering that brings together everything they love from BT Sport and Eurosport UK,” said Andrew Georgiou, president and managing director of Warner Bros Discovery Sports Europe.
Will this affect the coverage of the Premier League and Champions League and which sports are included?
As it stands before the joint venture, BT Sport and Eurosport already hold an impressive portfolio between them that gives each UK rights, in some cases exclusive, to broadcast various world sports.
This includes live coverage of the Olympics, Premier League, Champions League and other Uefa club competitions, tennis grand slams, Premiership rugby, overseas cricket, cycling grand tours, MotoGP, boxing, winter sports and UFC.
How much will it cost?
Currently, a monthly subscription for BT Sport costs £25, with one for Eurosport costing £6.99, although various offers are available depending on the package.
The companies have yet to unveil a pricing system and how it will cost customers to use its new joint services.
However, prices could rise for subscribers as the business seeks to increase coverage under one umbrella, especially if the platforms plan for all customers of one to have 'free' access to the content of the other.
It is unknown whether customers will be able to pay for one service or whether they will be forced to pay for both under a new payment plan.
Can customers opt out of content from either provider?
It is yet unclear whether current and new users on both platforms will be able to opt out of content they do not wish to watch, thereby potentially paying less.
"Our growing portfolio of premium entertainment content promises to deliver consumers a richer and deeper content proposition, not only providing greater value from their subscriptions but bringing sport to a wider entertainment audience," Andrew Georgiou, president and managing director of WBD sports Europe said.
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