The Associated Party Transactions (APTs) regulations are intended to prevent companies associated with the owners of football clubs from deliberately paying over the odds for deals with the clubs themselves.
The rules were brought in following the Saudi takeover of Newcastle United in an attempt to stop wealthy owners from using these link-ups to boost their teams' revenues so they can spend more money without breaking financial fair play rules.
In City's case, the rules led the Premier League to reject a new sponsorship deal the club had lined up with Etihad late in 2023, as well as a second agreement with an Abu Dhabi-based bank.
A panel of three retired judges has now ruled the league was wrong to stop the deals because elements of the ATP regulation breaches the Competition Act.
Man City have won their legal challenge against the Premier League's sponsorship rules
Pep Guardiola's side took legal action against these sanctions that they deemed as a form of 'discrimination' in February
City's title rivals Arsenal were among eight teams to provide evidence against the champions
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It's now been revealed that eight of the current top-flight teams provided evidence against the Premier League champions - including Arsenal and ประกันภัย Man United.
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Along with City's two rivals, Wolves, Liverpool, West Ham, Brentford, Bournemouth and Fulham all provided evidence against Pep Guardiola's side.
City's next match, which takes place at Molineux on October 20th, sees them take on Wolves, which could lead to a frosty affair in the directors' box.
The decision will send shockwaves through English football and is being seen as a major blow for Premier League chief executive Richard Masters because it will change the direction of the league's future financial governance.
It could even affect future results by making it easier for clubs with super-rich owners to arrange lucrative sponsorship deals, as well as making it easier to buy and sell players between clubs with the same owners.