United Technologies Corp. has won its appeal of government claims it was overcharged for Pratt & Whitney jet engines.

U.S. Circuit Judge Jeffrey Sutton of the 6th Circuit U.S. Court of Appeals in Ohio said Monday the government had the burden of proving damages “and it never did.” He remanded the case to the trial court that ordered the Hartford conglomerate to pay $657 million in damages.

The Department of Justice accused Pratt & Whitney of violating the False Claims Act, resulting in alleged overpayments for F100 jet engines from 1985 to 1990. The government said Pratt inflated its estimated costs for some parts and withheld data that would have disclosed the overstatements.

Spokesman John Moran said United Technologies looks forward to returning to the district court to end the case.