United lost 3-2 after four minutes of injury time, which Ferguson attacked afterwards.
"They gave us four minutes [injury time], thatís an insult to the game. It denies you a proper chance to win a football match," he said.
"There were six substitutions, the trainer came on, so thatís four minutes right away and the goalkeeper must have wasted about two or three minutes and they took their time at every goal kick.
"Thatís obvious to everyone today and itís a flaw in the game that the referee is responsible for time keeping. Itís ridiculous that itís 2012 and the referee still has control of that."