Rupert Murdoch's Fox said it filed an arbitration claim over the value of its stake in FanDuel, a fast-growing sports-betting business majority-owned by Paddy Power owner Flutter Entertainment.
The dispute goes back to a deal the two companies made when Flutter was acquiring the Stars Group in North America in 2019.
Fox, which already had a business venture with Stars, agreed to acquire an option on an 18.5% interest in FanDuel, a business Flutter controlled.
Mr Murdoch said the valuation should be based on what Flutter paid the minority shareholders of FanDuel for their stake last year.
“That’s our reading of it,” Mr Murdoch said.
Flutter rejected Fox’s claim and said it would “vigorously defend its position in the arbitration,” in a statement on Wednesday.
Flutter's drive into the deregulating US has paid off. Its shares fell by 3% in Dublin trade but are still up 118% in the past year, to value the Paddy Power owner at €31.3bn.
The US market value of sports-betting operators has soared in the past year as more states have legalised such wagers and consumers have embraced the pastime.
Flutter merged its US business with FanDuel in 2018 in a deal that valued FanDuel at less than €845m.
That deal is also the subject of litigation from FanDuel’s founders and earliest employees. In December, Flutter paid $4.18bn (€3.5bn) for the 37.2% stake in FanDuel owned by a group of institutional investors.
Fox and Flutter still have much to work out in their relationship. Flutter has said it’s exploring a possible public offering of FanDuel. The two companies have another competing joint venture, FoxBet, which Fox has been heavily promoting on its TV networks.