Nine clubs sanctioned by Uefa over Super League project as Barcelona, Real Madrid and Juventus hold out

Barcelona, Real Madrid and Juventus refuse to sign 'Club Commitment Declaration

Fans gather outside the stadium to protest against the European Super League prior to the La Liga match between Cadiz and Real Madrid on Wednesday, April 21. Getty

Fans gather outside the stadium to protest against the European Super League. Getty

Fans gather outside the stadium to protest against the European Super League. Getty

The Cadiz team bus is welcomed in by fans prior to the La Liga match against Real Madrid. Getty

Fans gather outside the stadium to protest against the European Super League prior to the La Liga match between Cadiz and Real Madrid. Getty

Cadiz's Alvaro Negredo, left, and Salvi Sanchez wear t-shirts that read in Spanish: "Super League? Soccer belongs to everyone" and "Soccer belongs to supporters" prior to the match. AP

Karim Benzema scores their first goal against Cadiz rom the penalty spot. Reuters

Real Madrid's Alvaro Odriozola celebrates scoring their second goal against Cadiz. Reuters

Karim Benzema scores the third. Reuters

Karim Benzema celebrates. Reuters

Real Madrid president Florentino Perez arrives at a radio station to give an interview. Reuters

Uefa announced sanctions against nine of the 12 clubs behind the aborted Super League project after the clubs "apologised".

European football's governing body said that "in a spirit of reconciliation" the nine clubs had agreed to a "Club Commitment Declaration" and accepted a five per cent cut in their European revenue for one season and acknowledged their "mistakes".

However, three clubs, Barcelona, Real Madrid and Juventus, did not sign the declaration.

Uefa said it "reserved all rights to take whatever action it deems appropriate against those clubs that have so far refused to renounce the so-called 'Super League'."

It concluded: "The matter will promptly be referred to the competent Uefa disciplinary bodies."

The maximum punishment Uefa can impose on the three rebel clubs is a two-year ban from European competition.

However, their options are clouded by a ruling from a commercial court in Madrid on April 20.

The court banned Uefa and Fifa from making any moves to block a Super League or taking any disciplinary measures against the clubs, players or officials involved.

It is also unclear what penalties the clubs that have withdrawn may owe to the remaining clubs for breaking their agreement to join the Super league.

The nine clubs that opted out of the project - Tottenham Hotspur, Arsenal, Manchester City, Manchester United, Chelsea, Liverpool, Atletico Madrid, Inter Milan and, the last to withdraw, AC Milan - have agreed to a series of "reintegration measures".

"These clubs recognised their mistakes quickly and have taken action to demonstrate their contrition and future commitment to European football," said Uefa president Aleksander Ceferin.

"The same cannot be said for the clubs that remain involved in the so-called 'Super League' and Uefa will deal with those clubs subsequently."

The nine have agreed to forego five per cent of their revenue from Uefa competitions for one season and pay, between them, a €15-million ($18.25 million) donation to support grassroots and youth football in Europe.

A spokesperson for Manchester United confirmed the Glazer family, which owns the club, would cover their club's share of both sums.

They also committed to participating in Uefa competitions for which they qualify and agreed to pay fines of €100m if they ever seek to play in an "unauthorised" competition.

Manchester United supporters stormed Old Trafford before the game against Liverpool on Sunday, May 2. The game had to be postponed as a result of the protests against United's American owners. AFP

Supporters protest against Manchester United's owners at Old Trafford. AFP

Manchester United supporters on the Old Trafford pitch before the game against Liverpool. AFP

Supporters protest against Manchester United's owners - the Glazer family - inside Old Trafford. AFP

Manchester United supporters protest against the Glazer family. AFP

United fans protest against the club owners. AFP

Fans protest against Manchester United's owners. Getty

Fans took part in a massive protest at Old Trafford on Sunday. Getty

Fans protesting against Manchester United's owners. Getty

Fans hold up banners as they protest against the Glazer family at Old Trafford. PA

Fans protest against the Glazer family before Manchester United's match against Liverpool. PA

Supporters protest against Manchester United's owners at Old Trafford. AFP

United fans clash with police outside of Old Trafford. AFP

United fans hold flares during the protest at Old Trafford. PA

Fans protest against the United owners outside Old Trafford. AFP

United fans clash with police outside of Old Trafford. AFP

United fans clash with police outside of Old Trafford. AFP

United fans clash with police outside of Old Trafford. AFP

United fans clash with police outside of Old Trafford. Reuters

"It takes a strong organisation to admit making a mistake especially in these days of trial by social media. These clubs have done just that," said Ceferin.

"In accepting their commitments and willingness to repair the disruption they caused, Uefs wants to put this chapter behind it and move forward in a positive spirit."

Earlier on Friday, Manchester United co-chairman Joel Glazer wrote to his club's fans saying he was "personally humbled" by their reactions and understood "why our initial support for the European Super League left you feeling angry and let down."

"I would like to reiterate my sincere apology for the mistakes that were made," he said.