FILE PHOTO: The Airbus A320neo (New Engine Option) takes off during its first flight event in Colomiers near Toulouse, southwestern France, September 25, 2014. REUTERS/Regis Duvignau/File Photo

GENEVA (Reuters) - The World Trade Organization's appeals judges will rule next week on whether the United States has grounds to slap trade sanctions on European Union for subsidizing planemaker Airbus AIR.PA, they said on Monday.

The ruling on whether the EU removed illegal subsidies for Airbus will end 14 years of litigation, leaving only the question of the amount of trade sanctions to be set if the EU loses the appeal.

U.S. trade lawyers have argued that the EU failed to undo subsidies worth $22 billion, costing the United States tens of billions in lost exports. But EU officials dispute that number.

The appeal ruling, due no later than May 15, ties up one half of the EU-U.S. long-haul transatlantic legal battle, with a parallel ruling in the EU's complaint about U.S. planemaker Boeing BA.N running some months behind the Airbus case.