Manufacturer United Technologies will pay the US Department of Defense $283m (£152m) after a probe into its handing of contracts over 20 years.
The US company’s Pratt & Witney jet engine unit is settling a claim for work over-charged through its accounting system.
United said the bill was larger than anticipated, but would have little impact on its 2006 financial results.
The firm also supplies the US military with Black Hawk helicopters.
Other United businesses include making Carrier air conditioners and Otis lifts.
The disputed work, between 1984 and 2004, involved making jet engine parts for commercial airlines in a collaborative programme with the US Department of Defense.
Since 2005 it has used a different accounting method which has been approved by the government.