GENEVA - The European Union has failed to stop subsidies to aircraft maker Airbus that were found to flout global trade rules, the World Trade Organiziation said Thursday.
An Airbus A380 aircraft performs during a flying display at the Farnborough Airshow, south west of London, on July 14, 2016
The WTO ruling hands a victory to US rival Boeing in the latest twist to a years-long trans-Atlantic trade dispute over government subsidies.
Boeing immediately said that the US could levy retaliatory duties against the EU of up to $10 billion a year after the WTO ruling.
For its part, Airbus denied it was breaking WTO rules and said it would appeal the ruling.
"We only needed to make limited changes in European policies and practices to comply," said Airbus, adding that the firm "did what we needed to do and did it in the agreed timeframe."
"We will address the few still remaining points indicated by the report in our appeal," concluded Airbus.
In its ruling, the WTO said that "the European Union and certain member States have failed to implement the recommendations and rulings of the DSB (Dispute Settlement Body) to bring its measures into conformity with its obligations" under international trade rules.
The case, which pits the US against its close trading partners the EU -- as well as France, Germany, Spain and Britain -- began in 2004 over alleged government handouts that fall foul of international trade rules.
Both giants have won and lost complaints filed against the other at the Geneva-based WTO.
In December 2011, the EU said it had submitted a "package of actions that achieves full compliance" with the WTO ruling.
But the US disagreed and asked the WTO to rule on the issue.
In parallel, the EU launched a separate dispute against the US over alleged subsidies to Boeing.
The tit-for-tat dispute began when the US accused Brussels of overstepping a 1992 bilateral agreement allowing aviation companies on both sides of the Atlantic to receive limited amounts of aid.
Washington and Brussels have 20 days to lodge an appeal to the latest ruling.