The United defender has been fined £45,000 and warned as to his future conduct in relation to a comment posted on Twitter.
It was confirmed on Friday that an Independent Regulatory Commission found proven the charge.
The statement added: "The Commission decided that the comment was improper and brought the game into disrepute. In addition, the Commission found that the breach included a reference to ethnic origin, colour or race.
"Both The FA and Manchester United were served the reasons on Wednesday 15 August 2012 and the deadline for appeal passed at noon on Thursday 16 August 2012."