Online gambling technology provider NYX Gaming Group has filed an anti-trust lawsuit against UK bookmakers William Hill for its efforts to block NYX’s acquisition by Scientific Games Corporation.

Last week, the Toronto-listed NYX went public with its claims that Hills, which holds a significant stake in NYX, was threatening to vote down the proposed C$775m acquisition of NYX by Scientific Games unless Hills received certain contractual assurances regarding NYX asset OpenBet, which powers Hills’ sports betting platform.

On Thursday, NYX filed a lawsuit in New Jersey Superior Court accusing William Hill Plc, William Hill Steeplechase Ltd and certain Hills officers and directors of engaging in “wrongful conduct in violation of the New Jersey Antitrust Act” by threatening to block the Sci-Games deal, which NYX claims would provide “great benefits to the nascent regulated sports betting industry.”

Hills provided around £90m to aid NYX’s 2016 acquisition of OpenBet, and Sci-Games’ interest in NYX is widely viewed as a play to position the company in the event that the US Supreme Court sides with New Jersey’s bid to overturn the federal PASPA sports betting prohibition.