Rolls-Royce Group Plc (RR/) must lower the $3.7 billion in damages sought in a patent lawsuit against United Technologies Corp.'s Pratt & Whitney because the jet- engine maker overstated the effect of competition, a judge ruled.

Estimates for engine prices, units sold and the value of service contracts are “based on misstatements of the law, a lack of sound evidence, and unsupported economic assumptions,” U.S. District Judge Leonie Brinkema in Alexandria, Virginia, said in a May 4 ruling.