Manchester City have been banned from European competitions for the next two seasons for "serious financial fair-play breaches", UEFA announced on Friday.
The English champions, who were also fined 30 million euros ($32.5 million), immediately announced they were appealing the suspension to the Court of Arbitration for Sport (CAS) "at the earliest opportunity".
"Manchester City is disappointed but not surprised by today's announcement by the UEFA Adjudicatory Chamber," the club said.
"The... flawed and consistently leaked UEFA process he (the UEFA chief investigator) oversaw has meant that there was little doubt in the result that he would deliver...
"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" at CAS.
Pep Guardiola's City face Real Madrid in this season's Champions League last 16.
Announcing the ban a UEFA statement declared: "The Adjudicatory Chamber has imposed disciplinary measures on Manchester City Football Club directing that it shall be excluded from participation in UEFA club competitions in the next two seasons (ie. the 2020/21 and 2021/22 seasons)."
European football's governing body said that City "failed to cooperate in the investigation".
"The adjudicatory chamber, having considered all the evidence, has found that Manchester City Football Club committed serious breaches of the UEFA Club Licensing and Financial Fair Play Regulations by overstating its sponsorship revenue in its accounts and in the break-even information submitted to UEFA between 2012 and 2016," European football's governing body said.
City lost a previous appeal to CAS over UEFA's original decision to refer them to its adjudicatory chamber over the alleged FFP violations.
The investigation into City was based on leaked emails published last year by German magazine Der Spiegel as part of "Football Leaks".
Guardiola's City outfit currently sit second in the Premier League table, meaning that the fourth Champions League slot available for English teams would likely go to the fifth-placed club this term.
Sheffield United, promoted to the top flight last year, sit in fifth.
It is not the first time that Man City have fallen foul of FFP regulations, having been fined 60 million euros and seeing their Champions League squad reduced in May 2014.
Qatari-owned Paris Saint-Germain were also fined that year.
Seven-time European champions AC Milan were banned from this season's Europa League for FFP breaches.