Real Madrid won the 2016 Champions League in May, beating city rivals Atletico Madrid on penalties in the final

BT Sport has extended its TV rights for the Champions League and Europa League until 2021 in a deal worth £1.2bn.

The company has been broadcasting Europe's elite club competitions since 2015 under the terms of an £897m deal agreed in 2013.

BT Sport, owned by Britain's biggest broadband and mobile operator BT, is a paid subscription service.

But it said it would make clips, weekly highlights, and both finals available to watch for free on social media.

The new deal gives BT Sport exclusivity across all live games and highlights for the first time - meaning there will be no weekly highlights shown on free-to-air broadcaster ITV.

Europe's top four domestic leagues are to be guaranteed four places each in the group stages of the Champions League from the 2018-19 season.

Other changes to the competition will see 'double-header' nights in the group stage, with matches kicking off at both 18:00 and 20:00 UK time.

The current top four leagues according to European governing body Uefa's rankings are Spain, Germany, England and Italy.

Under the present system, England, Germany and Spain have three places each while their fourth-placed teams must win a play-off to qualify.

Analysis

BBC sports editor Dan Roan

After recent falls in viewing figures and concerns over the threat of illegal streaming, there was mounting expectancy that the relentless inflation in football rights over the last two decades may finally be coming to an end. So much for that. BT have paid 35% more for Uefa's rights that they did last time, a reminder of the importance communications companies attach to live football as a means of attracting customers to a range of services.

Despite concerns by sponsors over reduced exposure with the loss of free to air live coverage, Uefa has now gone even further, handing BT the highlights rights too. For Uefa, this will help appease the clubs and national football associations, who will get yet more money, but has clearly dismayed many fans.

However, in a reflection of the way viewing habits are changing, especially among younger audiences, BT has agreed to make some content available for free via social media, a tactic that many rights holders could now look to copy.