US media giant Comcast has bid £22.1 billion to take over UK broadcaster Sky, setting up a battle for the company with Rupert Murdoch's 21st Century Fox.
The owner of CNBC and Universal Pictures wants to snap up a majority stake in the Game Of Thrones broadcaster - more than 50% - and was confident a deal would be given the green light by regulators.
Such a move would place Sky at the centre of a full-blown takeover tussle, with Rupert Murdoch's Fox struggling to buy the 61% of the broadcaster it does not already own due to mounting regulatory hurdles.
The Comcast offer is £12.50 per share, which is 16% higher than Rupert Murdoch's 21st Century Fox's bid of £10.75 per share.
It said the move would create a "leading content and distribution business in the UK and Europe".
Shares in Sky surged more than 18% in morning trading on the London Stock Exchange following the announcement.
Comcast chairman and chief executive Brian Roberts said Sky is "an outstanding company".
"We intend to maintain and enhance Sky's business," he added.
Comcast, which has a broadband arm serving 29 million US customers, said international revenues would surge by between 9% and 25% if the deal goes ahead.
It also pledged to ensure the future of Sky News, a flashpoint in Fox's £11.7 billion takeover bid because of regulatory concerns over Mr Murdoch's dominance over UK media.
While Comcast has a "substantial" UK operation employing 1,300 staff, the company believes its approach will not spark concerns over media plurality because of its "minimal presence" in UK media.
A potential takeover battle between Comcast and 21st Century Fox also has the potential to complicate Walt Disney's $66 billion (£47 billion) attempt to buy Fox's entertainment assets, including Sky.
ITV News business editor Joel Hills says one of the commitments the Comcast chairman has made to Sky's existing business is to fully maintain funding for Sky News, which goes beyond the five year funding commitment made by Fox.
The Comcast move comes after the UK competition watchdog found Fox's deal to buy Sky was "not in the public interest".
The Competition and Markets Authority had suggested ways Fox could address its concerns, including spinning off Sky News, or "behavioural" changes to protect Sky News from direct influence from the Murdoch Family Trust.
Fox has offered to shield Sky News from Mr Murdoch's influence and guarantee the existence of the news service for at least 10 years as part of a series of so-called "firewall remedies".
The CMA has until May 1 before sending its final report on the Fox bid to Culture Secretary Matt Hancock, who will then have 30 working days to make a final decision.