Fox said it would pay 10.75 pounds per share - or 11.7 billion pounds - for the 61 percent of Sky it does not already own to control a business with 22 million customers in Britain, Ireland, Italy, Germany and Austria.
People familiar with the matter told Reuters the American media corporation pounced after Britain's vote to leave the European Union in June sent the pound down about 15 percent against the U.S. dollar and Sky's share price tumbling.
The Murdoch family have never wavered in their ambition to take full control of Sky, despite the damaging failure of a previous attempt five years ago when their British newspaper business became embroiled in a phone-hacking scandal.
The agreement comes just over a week after Fox first approached Sky and follows several days of haggling in London which resulted in Fox lifting its offer three times to secure the backing of Sky's independent directors, according to two people familiar with the situation. The deal values all of the company at 18.5 billion pounds.
James Murdoch, the chief executive of Fox and chairman of Sky, said the British-based company had led the way in delivering premium content like English Premier League football and the "Game of Thrones" fantasy drama across multiple platforms including satellite, broadband and mobile.
"Sky is much more than a satellite distribution company, it's a creative, commercial and consumer powerhouse," the son of 85-year-old business patriarch Rupert told analysts on a call.
The deal is the latest one to marry distribution with content after AT&T Inc announced an $85 billion bid to buy Time Warner Inc earlier this year.
PHONE HACKING
After winning the backing of Sky's independent directors, Fox will need to secure regulatory approval in Europe and Britain and win over those Sky shareholders who believe the price is too low.
Four top-50 shareholders told Reuters on Thursday that, while they thought the bid was still on the low side, they were being pragmatic due to Fox's ownership of 39 percent and would accept the offer.
Fox will pay a 200-million-pound break fee if it fails to pull off the deal, and has opted for a scheme of arrangement. This means that the bid must win the backing of shareholders representing 75 percent of the Sky stock not owned by Fox.
Rupert Murdoch has dominated Britain's media and political landscape for decades, with former prime ministers Margaret Thatcher, Tony Blair and David Cameron securing the media mogul's blessing and the backing of his papers. Critics say this has given him too much sway in Britain.
The re-emergence of the Sky deal shows he believes the reputational damage caused by the phone-hacking scandal at the now-defunct News of the World tabloid is behind them.
Since the scandal exploded in 2011, he has split his business into two parts, with Fox housing the TV assets and his newspapers owned by News Corp.
James Murdoch said he expected the deal to pass "regulatory muster" and, as long as regulators looked at the facts around media ownership, no "meaningful concessions" would be required.
But critics will argue that despite the split, Murdoch and his sons James and Lachlan still control both firms.
BREXIT BARGAIN
The new Sky offer has already sparked concern, with several politicians attending a debate in parliament this week to urge the government to properly scrutinise the deal.
The price of 10.75 pounds per share, representing a premium of around 40 percent on the day before the initial proposal was received, has also disappointed several top-50 shareholders who accused Sky of selling out too cheaply to their founder and biggest shareholder.
Sky's stock is in a trough, down 32 percent this year before Murdoch made his move, on worries about the strength of the economy in Britain after Brexit, its biggest market, while investment in content and a new mobile service has weighed on earnings.
But investors say Sky has a reputation for seeing its investments pay off and that the firm's earnings will rebound.
Shares in Sky were trading almost a pound below the offer price ahead of a regulatory process that is likely to take some time. Fox said it expected the acquisition to complete before the end of 2017.
Fox will take on about $10 billion of debt to fund the deal, but said it would pay this down as quickly as possible.
Deutsche Bank, Centerview Partners, Goldman Sachs and J.P. Morgan advised Fox while Morgan Stanley, PJT Partners and Barclays advised Sky.
(Additional reporting by Sophie Sassard and Carolyn Cohn)
By Kate Holton and Paul Sandle
