The 21-month Fox-Comcast bidding war for Sky, Europe’s largest pay-TV operator, will come to an end by this weekend.

A UK regulator said Thursday that, barring a settlement, a three-round bid process will take place on Saturday — after which a winner will be named.

Both Fox and Comcast have agreed to the process, UK’s Takeover Panel said. The regulator ordered the current auction process to end at noon in New York City on Friday.

Comcast now has the highest bid, so Fox, which already owns 39 percent of Sky — offering $18.50 per share in its latest offer for the remaining 61 percent — will bid first on Saturday.

If the Fox offer tops Comcast’s current high bid of $19.50, the cable operator, in a second round, will be able to submit an even higher price.

If Comcast does keep the auction alive, a third and final round will be held, with both companies submitting simultaneous bids.

Barring a tie, the regulator will announce a winner Saturday evening in London.

Fox’s bid for Sky is backed by Disney, which agreed in June to buy Fox’s TV and film assets, including its existing Sky position, for about $71 billion.