U.S. planemaker Boeing received billions of dollars of unfair subsidies from the U.S. government, the World Trade Organization said on Thursday.
The subsidies included banned support in the form of research and development aid from the NASA space agency.
The ruling by a panel of trade judges is the latest chapter in a six-year battle over state support for the industry's two giants in what has become the world's largest trade dispute.
A separate WTO trade panel condemned European support for Boeing rival Airbus in a parallel case last year.
(Reporting by Andrew Callus, Tim Hepher)