CAS cut the ban to four years however, saying the punishment by Fifa was "too severe." A fine was also reduced. Platini announced that he would resign as Uefa president.
The court "was not convinced by the legitimacy of the 2,000,000 Swiss franc ($2 million, 1.8 million euros) payment, which was only recognised by Mr. Platini and Mr. (Sepp) Blatter, and which occurred more than eight years after the end of his work relations," said a statement from the tribunal based in Lausanne, Switzerland.
"The suspension of Mr. Platini has been lowered from six to four years and the 80,000 Swiss franc fine (reduced) to 60,000," the court said in ruling on an appeal filed by Platini in February.
In a statement, Platini, who had hoped to resume his role as president of Uefa in time for the Euro championships in June, said the decision was a "deep injustice".
He would resign from his post at Uefa "in order to be able to pursue my fight in the Swiss courts to prove my integrity," he said.