FIFA suspended Suarez from his next nine matches and banned him from playing football for four months.
In a letter submitted to the organization one day after the incident, Suarez said that he accidentally bit Chiellini.
"After the impact I lost my balance, that destabilized me and I fell on top of my opponent. At this moment I hit my face against the player leaving a small bruise on my cheek and a strong pain in my teeth and that's why the referee stopped the match. That is what happened and in no way was there any case of biting or intending to bite," he wrote.
The FIFA panel ruled against Suarez on Thursday, finding that "he bit the player with the intention of wounding him or at least of destabilizing him."