Comcast Corp. (CMCSA - Get Report)  will face rivals Walt Disney Co. (DIS - Get Report) and 21st Century Fox (FOX)  Friday in the latest clash in a months-long, multi-billion dollar takeover battle to create a transatlantic media empire that could cost as much as $65 billion.

But the two-day, three-round auction fight may not be the final act in the long-running drama to control Britain's Sky plc (SKYAY)  and its 23 million customers across five European countries.

Sky has been at the center of a battle between Disney CEO Bob Iger and his opposite number at Comcast, Brian Roberts, to expand their entertainment groups after Iger outbid American's biggest cable company for the right to buy media assets from Rupert Murdoch's Fox for just over $71 billion. Iger's win, however, came with cost: Comcast's involvement added some $20 billion to Disney's overall price tag and complicated its efforts to control Sky, whose platform is crucial for the House of Mouse's ambitions to roll-out a global digital streaming service to challenge Netflix Inc. (NFLX - Get Report) .

The bad blood could come to a boil later today, however, in a rare three-round auction established by the U.K. takeover panel that kicks off at 5:00 pm London time (noon eastern) and pits Iger and Roberts in a head-to-head contest to convince Sky investors to tender their shares. 

Disney, which has a de-facto £14 per share bid for Sky on the table thanks to its soon-to-be ownership of Fox, will put forward its revised bid in the first round. Comcast, which trumped that Fox/Disney bid in early July with an all-case approach valued at £14.75 will follow in the second round and may have an advantage in that it will see what Disney/Fox has submitted.

Both will get a chance to got to "best and final" offers in the third round, at which point the Takeover Panel will declare a winner, or determine a tie. 

In either case, Sky shareholders will have two weeks to decide if they wish to tender their holdings to the highest bidder, a preferred bidder or remain invested in the London-based broadcaster. 

Activist investor Crispin Odey, who founded Odey Asset Management, has said he thinks the bidding could reach £18 a share, a price that would value the group at £50 billion ($66 billion). Macquarie's Guy Peddy thinks the outcome is likely to be closer to £16.50 per share.

Sky shares were marked 0.35% higher in London trading Friday and changing hands at £15.85 each, a move that extends their year-to-date gain to 58.3% with a market value of just under £27 billion.

Disney shares were marked 1.86% higher in pre-market trading in New York Friday, indicating an opening bell price of $113.70 each, a move that could take its year-to-date advance to around 5%. Comcast was little-changed from last night's close at $37.80 but is down around 5.5.% for the year.

On face, however, Comcast would seem to the have the edge: its £14.75 offer is superior to Disney/Fox, and it has received quick and easy regulatory clearances from regulators in both Europe and the United Kingdom. 

However, given that Disney/Fox already owns 39% of Sky, Comcast faces a higher barrier in terms of convincing other shareholders -- including activists such as Elliott Management -- to chose its approach: Roberts needs 80% of the outstanding 61% of shares to get majority control. Fox only needs to boost its take by 11%.

Disney/Fox also has the option of holding on to its stake even if Comcast prevails, a tactic which would allow it to wait-out changes in the global streaming and media landscape, particularly following next year's EU exit by the United Kingdom and the evolving regulations on data privacy and media hegemony from both London and Brussels.

The European media sector is also undergoing major changes, with Italy's Mediaset, the nation's biggest private broadcaster, hinting earlier this month that they're "working on something big and something complex", according to CEO Pier Silvio Berlusconi, following its failed takeover of France's Vivendi.

Disney/Fox, along with activists who've booked some pretty solid gains and are playing with house money -- Sky has risen some 58.3% since the start of the year -- couldn't be blamed for wanting to watch those developments unfold before cashing out.

So, while the Takeover Panel has said it will reveal the results of the auction as soon as it is "practically possible" following the conclusion of the auction on Saturday, or at the very latest at 7:00 am London time on Monday September 24, the final word on the fate of Sky -- and the international ambitions of both Disney and Comcast, may not be known for a long time after.