The federal court jury in Albany, which deliberated for more than nine hours over two days before reaching the verdict, also decided that Tyson did not have just cause to sack Rooney in 1988.
Tyson, who was sued for pounds 30.62m by Rooney, described the verdict as "ridiculous" and said: "If Kevin would have asked me for four million dollars I would have given it to him."
In the lawsuit, Rooney accused the boxer of failing to honour a verbal contract made by Tyson's late mentor, Cus D'Amato, promising him a lifetime job with a guaranteed 10 per cent of the boxer's winnings.
Tyson's lawyer had countered that the boxer knew nothing about such a contract. "I'm satisfied," Rooney said after the ruling.
"I never expected 49 million but you can't take blood from a stone. They came in with what they feel is a just verdict and I'm not going to argue with it."
"I am going to appeal against this unjust decision," said Tyson, who had testified that he had parted company with Rooney after becoming angry at the trainer for talking publicly about his marriage to the actress Robin Givens and his contract dispute with his former manager Bill Cayton.
Prince Naseem Hamed yesterday broke off training for his next world title fight to receive the Board of Control's Boxer of the Year award in London.
Hamed's award for his outstanding year was presented at a board lunch by the new chairman Leonard "Nipper" Read.
The World Boxing Organisation featherweight champion from Sheffield, who faces Argentina's Remigio Molina at Manchester's Nynex Arena on 9 November, is looking ahead to a fruitful 1997, in which the formidable Mexican Marco Antonio Barrera could be on his agenda.
Before then, Hamed could be making an assault on the International Boxing Federation title of Tom "Boom Boom" Johnson in February.
The now-retired Frank Bruno received a special tribute for his major contribution to British boxing, while the overseas Boxer of the Year statuette went to South Africa's WBO light-flyweight champion, Baby Jake Matlala.
The British Fight of the Year was the titanic super-featherweight title clash between P J Gallagher and Charles Shepherd at Erith Leisure Centre in Kent on 29 June.Reuse content