Murdoch's Fox agrees on bid for UK's Sky

21st Century Fox has paid more than $US32 billion for Britain's Sky TV network.

Rupert Murdoch's 21st Century Fox has bought Sky Broadcasting in the UK. (AAP)

Rupert Murdoch's 21st Century Fox says it had agreed to a deal to buy Britain's Sky with an offer valuing the pay-TV group at $US32.5 billion, trumping rival bidder Comcast.

Fox, which is expecting to get regulatory approval from Britain this week after striking an initial deal with Sky in December 2016, upped its offer to 14 pounds per share, from its earlier 10.75 pounds per share.

The price agreed, which represents an 82 per cent premium to the price of Sky's shares in December 2016 before Fox's initial offer, is at a multiple of 21 times 2017 earnings per share, Fox said.

But Fox may still face further competition from US cable giant Comcast which submitted its own bid for Sky in February, valuing the pan European group at 12.50 pounds per share.

Sky's shares closed at 15.01 pounds on Tuesday, meaning shareholders may also not like the price.

Fox, which already owns 39 per cent of Sky, said it had secured the agreement of the independent committee of Sky for the deal.