Judge Miriam Cedarbaum found that Rahman, who knocked out Lewis on April 22 to win the WBC and IBF world heavyweight titles, breached a contract he had signed to give the Briton a rematch within 120 days of their first fight in South Africa.
By signing a deal with promoter Don King in May to fight Nigerian David Izon in China on August 4, Rahman, 28, has breached the contract he signed with Lewis, said Cedarbaum.
She added that the American could have fought an interim fight within the time allowed, but that when he did not the original contract was “binding and enforceable”.
Referring to arguments that Lewis would be irreparably harmed by not having an immediate rematch, Cedarbaum said there was “credible evidence” that Lewis would not be able to fight beyond the next two years.
She was referring to testimony that a boxer has a finite physical peak and that the 35-year-old was not planning to fight beyond the next two years.
“Lennox Lewis has only two more years to fight. He is not in position to go on indefinitely,” said Cedarbaum.
“Since Mr Lewis can’t fight Mr Rahman beyond the next two years, Mr Rahman is enjoined for the next 18 months from fighting anyone else until he fights a rematch with Mr Lewis,” she said.
She added that “I would expect all parties to negotiate in good faith,” for the terms of the rematch.