The long-running takeover battle for Sky could end up going to a sealed bids auction if Comcast and Rupert Murdoch’s 21st Century Fox do not give their final offers by the end of next week.

US media giant Comcast and Fox have until September 22 to submit their best and final bids for the pay TV giant, but as the deadline nears the saga could end up taking another intriguing turn.

Comcast increased its offer for Sky to £26 billion in July, just hours after Fox hiked its bid for the 61% stake in the UK broadcaster that it does not already own to £24.5 billion.

Fox has yet to respond with a higher offer.

Absolutely Fabulous The Movie World Premiere – London
Fox owner Rupert Murdoch, pictured with wife Jerry Hall, sparked the takeover battle with an original £11.7 billion bid for Sky in 2016

The Takeover Panel will step in if the deadline passes at the end of next week without revised bids being submitted and neither firm confirms their bid is their final one.

It would bring to an end the protracted takeover tussle, which has been one of the most complex and convoluted in recent memory.

The battle to seize control of Sky has thrust the group to the centre of a global war between media giants Walt Disney and Comcast as they look to take on the might of Netflix and Amazon.

Mr Murdoch has long wanted to seize full control of Sky, having previously made an ill-fated attempt to buy it out in 2011.

But his latest move is part of a much bigger picture.

Since Fox made its original £11.7 billion bid in December 2016, it has agreed to sell a major chunk of its business – including the existing 39% Sky stake to US film behemoth Walt Disney.

If it can win the battle to buy Sky before the Disney deal closes, then Disney will take full ownership of Sky when it closes its own takeover of the Fox assets.

But it has found a determined rival in media and telecoms group Comcast – which owns NBC Universal and is the largest cable operator in the US.

If Comcast takes over Sky, it will become the biggest pay TV provider in the world, with around 52 million customers after adding Sky’s 23 million subscribers.

Fox has faced heavy scrutiny from the UK Government and competition watchdogs over its Sky takeover plans, while Comcast’s bid was cleared by regulators early on in the process.

Fox was finally given the Government’s all-clear to take over Sky in July, although it has had to pledge to offload Sky News to Walt Disney, and provide a Disney-owned Sky News channel with funding of at least £100 million a year for 15 years.

It is thought the Takeover Panel may look to clarify how the Sky auction would work before the September 22 deadline.

It is rare for the panel to run auctions in takeover situations, with Tata’s victory in acquiring UK steelmaker Corus in 2008 one of just a few in the past decade.