The £26 billion takeover battle for Sky is likely to come to a conclusion this weekend.
The Takeover Panel has announced that a three-round auction will take place on Saturday evening, assuming there was no clear bidder in the frame as of 5pm on Friday evening.
21st Century Fox and Comcast would compete in the auction that would begin with a fresh bid by Fox, currently the lowest of the two bidders. In the second round Comcast would be the only bidder permitted.
If there is still no clear bidder then both companies would be allowed to increase their bids in a third round.
Such auctions are rare and this would only be the fifth time one has been required to decide a takeover since the current rules came into place in 2002.