Brussels has said it would be “extremely concerned” if the defence group EADS was prevented from fairly bidding for a major US defence deal.
Its comments came after pan-European EADS and US partner Northrop Grumman abandoned a bid for a $35bn (£23bn) mid-air refuelling aircraft contract.
Northrop Grumman and EADS said the terms of the Pentagon tender “clearly favour” US aerospace giant Boeing.
Boeing is now widely expected to win the contract for the aircraft.