Uefa president Michel Platini will resign from European football's governing body after failing to have a six-year ban from football overturned.
A Court of Arbitration for Sport (Cas) panel reduced the ban to four years on Monday.
Following the judgement, the 60-year-old said he would be stepping down.
Platini and former Fifa counterpart Sepp Blatter were last year found guilty of ethics breaches over a 2m Swiss Franc (£1.3m) "disloyal payment".
Platini had taken his case to Cas seeking to get the ban overturned, but a three-man panel said it "was not convinced by the legitimacy of the payment".
The two said the payment in 2011 was made for consultancy work Platini had carried out for Blatter between 1998 and 2002, and that they had a "gentleman's agreement" on when the balance was settled.
The matter is also being looked into by Swiss prosecutors.
After Cas returned its judgement, Platini said in a statement: "I am resigning from my duties as Uefa president to pursue my battle in front of the Swiss courts to prove my innocence in this case."
He added that he considered the judgement "a profound injustice".
However, the Cas panel was damning of Platini, saying his "behaviour was not ethical or loyal".
It found his dealings with Blatter had breached the ethics code of world governing body Fifa, and while his six-year ban was "too severe", it decided a four-year punishment should be handed down - the equivalent to a presidential term in office.
It also said an 80,000 Swiss Franc (£57,200) fine should be lowered to 60,000 (£42,900), but stressed: "The Cas panel was of the opinion that a severe sanction could be justified in view of the superior functions carried out by Mr Platini (Fifa vice-president and Uefa president), the absence of any repentance and the impact that this matter has had on Fifa's reputation."
Uefa said it would meet on 18 May "to discuss next steps".
"In the meantime, there will be no Uefa president appointed ad interim," it added.