Published: 2020-02-15 02:14:53 BdST
UEFA said in a statement that City had committed "serious breaches" of the rules while the Premier League club swiftly said on their website that they will appeal the decision to the Lausanne-based Court of Arbitration for Sport (CAS).
The ruling, if upheld, would mean Pep Guardiola's side would not be able to compete in the 2020-21 Champions League should they again qualify for Europe's top club competition. They would also be banned from European competition in the 2021-22 season.
An absence from continental action would have a significant impact on the club's revenue as well as their prestige.
UEFA's FFP rules are designed to prevent clubs receiving unlimited amounts of money through inflated sponsorship deals with organisations related to the owners.
The Adjudicatory Chamber of UEFA's Club Financial Control Body (CFCB) said City had broken the rules by "overstating its sponsorship revenue in its accounts and in the break-even information submitted to UEFA between 2012 and 2016" and added that the club "failed to cooperate in the investigation".
But City, who have denied any wrongdoing, said in a strongly worded response that they will fight the decision.
"Simply put, this is a case initiated by UEFA, prosecuted by UEFA and judged by UEFA. With this prejudicial process now over, the Club will pursue an impartial judgment as quickly as possible and will therefore, in the first instance, commence proceedings with the Court of Arbitration for Sport at the earliest opportunity," the club said.
Describing themselves as "disappointed but not surprised" by the decision, City took aim at the investigation process.
"In December 2018, the UEFA Chief Investigator publicly previewed the outcome and sanction he intended to be delivered to Manchester City, before any investigation had even begun.
"The subsequent flawed and consistently leaked UEFA process he oversaw has meant that there was little doubt in the result that he would deliver. The Club has formally complained to the UEFA Disciplinary body, a complaint which was validated by a CAS ruling."
City are currently second in the Premier League and face Real Madrid in the last 16 of this season's Champions League.
UEFA had opened an investigation into City in March 2019 after German publication Der Spiegel alleged that the club’s Abu Dhabi owners had inflated sponsorship agreements to comply with FFP requirements.
The Abu Dhabi United Group, the investment vehicle owned by Sheikh Mansour bin Zayed Al Nahyan, is the majority owner of the City Football Group, with a stake of around 77%.
The City Football Group includes the Manchester club and owns or part-owns New York City FC, Melbourne City FC, Yokohama F. Marinos in Japan, Club Atletico Torque in Uruguay, Girona FC in Spain and Sichuan Jiuniu FC in China.
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