Boxer Amir Khan has been fined £1,000 and banned from driving for 42 days after a court heard evidence he was driving at speeds of up to 140mph.
Amir Khan already has a six-month driving ban
The Commonwealth lightweight title holder, who lives in Bolton, was found guilty of breaking the speed limit on the M62 in December 2006.
Khan, who denied the charge, was found guilty by magistrates in Rochdale.
In October, 21-year-old Khan was banned for six months after injuring a man when he sped through a red light.
A police officer told Rochdale Magistrates' Court that his speedometer was "off the clock" at 155mph as he pursued Khan on the M62 on New Year's Eve 2006.
District Judge Pamela Baldwin said there was insufficient evidence to prove Khan was driving at more than 100mph, but that she was satisfied it was in excess of 70mph.
Although Khan had denied speeding in his BMW convertible, during his trial he admitted his speed may have reached around 75mph.
Khan's suspension will run concurrently with the six-month ban he received last October after being convicted of careless driving when knocking down a pedestrian on a pelican crossing.
Pc Paul Saunders told the magistrates court he first saw Khan's car at junction 19 near Rochdale.
He said the car was in the outside lane going very fast and he decided to follow it.
He said: "I was in a Vauxhall Vectra. The speed was off the clock at 155mph, its maximum speed."
The officer said he told Khan he had been driving between 135mph and 140mph and he cautioned him.
Det Insp Geoffrey Amir, who was in the police vehicle, said that the pursuit was the "fastest he had ever travelled in a car". Both officers said Khan was alone in the car.
Khan said he had been returning home to Bolton after visiting friends in Leeds and was with two friends.
He told his defending solicitor, Don Rogers, that he was not driving fast.
"I was having a conversation with my friends. To say I was having a conversation and driving at up to 140mph is just not possible," he said.
Khan maintained he was driving at about 75 mph. Outside court, Khan maintained he did not reach speeds of up to 140mph.
He said: "I did not drive that fast. I am not a fast driver.
"I am pleased to get this over with and I have learned my lesson. It will never happen again."
Khan must also pay £790 court costs.