Walt Disney says it is to buy 21st Century Fox’s entertainment assets for a total $52.4bn (£39bn).
The deal includes Fox’s 39% stake in satellite broadcaster Sky, and the 20th Century Fox film studio, Disney announced.
Fox’s remaining assets, including Fox News and Sports, will form a new company.
The deal ends more than half a century of media expansion by Fox owner Rupert Murdoch, who is 86 years old.
He turned a single Australian newspaper he inherited from his father at the age of 21 into one of the world’s largest news and film empires.
Mr Murdoch’s shift to selling assets rather than buying them has come as a surprise to those who expected him to hand over the businesses to his sons, James and Lachlan.
James Murdoch had been widely tipped to be given a senior role at Disney. But Disney chief executive Bob Iger told Good Morning America: “James and I will be talking over the next couple of months. He will be integral to the integration process. He and I will be discussing whether there is a role for him or not at our company.”
Mr Iger will remain in his role until the end of 2021.
It is not clear how the deal will be received by US competition regulators.
The US Department of Justice recently sued to block AT&T’s $85.4bn deal to buy Time Warner, on the basis that it will raise prices for consumers and competitors.
Fox’s proposed deal to buy the remainder of Sky is being already investigated by the UK Competition and Markets Authority (CMA), which is due to publish provisional findings in January.
The BBC understands that the Disney deal will not alter that investigation.
Fox is selling assets including its FX and National Geographic cable channels and media company Star India.
Disney also will buy Fox’s stake in the Hulu video streaming service, giving it majority control of a competitor to Netflix.
Hulu is also partially owned by Comcast and Time Warner.
The deal will also add to Disney’s huge back catalogue, with high-grossing films such as the original Star Wars movie, Avatar and Deadpool, as well as TV hits including The Simpsons.
Mr Iger said that Disney was “incredibly excited” about the acquisition, and that it was an “opportunity to expand iconic franchises” such as Avatar and Star Wars.