Manchester City and the English Premier League both claimed victory on Monday after one of the league’s key regulations relating to financial fairness were challenged.

Four-time defending champion City and the league said they “welcomed” the findings of an arbitration panel. City said the regulations were found to be “unlawful” and the league “abused its dominant position.”

The league said the tribunal found the rules to be “necessary” and “rejected the majority of Manchester City’s challenges.”

The regulations in dispute, the Associated Party Transaction rules, are designed to ensure fair market value is applied to commercial deals with organizations closely aligned to club owners, and safeguard the “competitive balance” of the world’s most popular soccer league.

City said in a statement, “The club has succeeded with its claim: The Associated Party Transaction rules have been found to be unlawful and the Premier League’s decisions on two specific MCFC sponsorship transactions have been set aside.”

City added the tribunal found the rules to be “structurally unfair” and the league was “specifically unfair” in applying them to the Abu Dhabi-backed club.

One key finding in City's favor was that shareholder loans — which could be offered at lower or no interest rates — should not be excluded from APT rules.

City said decisions on two of its sponsorship deals were set aside following the tribunal.

While the league said a “small number of discrete elements of the rules” did not “comply with competition and public law requirements,” it added: “The tribunal upheld the need for the APT system as a whole and rejected the majority of Manchester City’s challenges. Moreover, the tribunal found that the rules are necessary in order for the league’s financial controls to be effective.”

In a separate case, City faces more than 100 charges of alleged financial breaches from the league.