Benitez made his complaints immediately after the 2-2 draw at Old Trafford last Sunday.
The Chelsea interim manager claimed he had been waiting for Ferguson, who then completely ignored him.
However, whilst there is little love lost between the pair, the United manager insists he would never ignore a handshake.
"It is absolute nonsense," said Ferguson.
"Why wouldn't I shake hands? Have you ever seen me not shake hands with anyone?
"I never saw him. I was signing autographs at the front and there was an Indian lad who always wants to shake hands before a game because he says it brings me luck.
"If he (Benitez) wanted to shake my hand he could have stood in front of me.
"I don't know why he has said that. It is nonsense."