Comcast Corp. (CMCSA - Get Report) , Walt Disney Co. (DIS - Get Report) and 21st Century Fox (FOX) will take their $35 billion battle to own Britain's Sky plc (SKYAY) into a one-day bidding contest that will determine the owner of Europe's most lucrative pay television broadcaster, regulators said Thursday.

The U.K. Takeover Panel, which oversees mergers and acquisitions, said a three-round bidding auction, which will being at 5:00 pm London time Friday, will determine the ultimate owner of the London-based broadcaster, which is 39% owed by Rupert Murdoch's Fox. The Panel said the bids will not be made public during the process, but will be revealed when the process is completed on Saturday the 22nd or by 7:00 am London time on Monday September 24.

"On the basis that neither (Comcast or Fox) has declared its offer final, such that either offer may be increased or otherwise revised, a competitive situation continues to exist for the purposes of Rule 32.5 of the Takeover Code," the Panel said in a statement Thursday.

Sky shares were marked 0.2% lower in London trading following the Panel's decision, and changing hands at £15.77 each, but have still roared more than 57% higher since the start of the year amid the ongoing takeover drama.

Sky was first placed on the selling block in December 2016, when Fox said it would pay £10.75 per share for the 61% of the group that it doesn't already own. That bid was immediately deemed too low for many shareholders, however, and was subject to significant pushback from U.K. authorities, including lawmakers who were concerned over the dominance that Murdoch, an American citizen born in Australia, would have over the British media landscape.

Comcast entered the fray in February 2018, announcing its intention to pay £12.50 a share for the 61% Sky stake as it sought to grow customers and profits outside of its home market in the United States. 

Fox quickly boosted its own offer to £14.00, only to see that trumped on the very same day by  Comcast's improved £14.75 bid, which was formalised with an offer document on July 13.

Amid this contest, of course, Fox agreed to sell its media assets to Disney for $71 billion in cash and shares, a move which meant that Bog Iger's 'House of Mouse' could either keep the 39% Fox stake in Sky that was included in the purchase, or sell it to Comcast and bank the estimated $10 billion in proceeds.

Disney, however, is looking to build a streaming entertainment service to rival Netflix Inc. (NFLX - Get Report) (which, interestingly, announced a commercial tie-up with Sky earlier this week) and Sky's 23 million customers could play a huge role in that idea's international expansion.