James McNerney, Boeing chairman and chief executive, expressed hope on Wednesday that the trade conflict between the US and the European Union over subsidies for the development of new commercial aircraft could be solved by negotiation rather than litigation.

The row over billions of dollars of alleged state subsidies given to Boeing and Airbus to support new generations of large passenger jets such as the Boeing 787 Dreamliner and the Airbus A380 superjumbo has triggered the biggest dispute in the history of the World Trade Organisation.