Porto have been fined £16,700 by UEFA as a punishment for the racist abuse that was directed towards Manchester City striker Mario Balotelli by the club's fans.
The incident occurred during City's Europa League trip to Portugal in February.
On numerous occasions when the Italian striker was in possession, certain sections of the ground were heard performing monkey chants.
The governing body's control and disciplinary board have decided that the offence warrants a fine and a warning over their future conduct.
Porto have three days to appeal the verdict.
