The amount of illegal subsidies paid through NASA were worth $2.6 billion over 1989-2006, said the arbitrators, who added that those paid through the Department of Defence research and development programme were "unclear." The WTO also found against tax breaks, particularly those given by the state of Washington as well as on the federal level, saying that these were subsidies. They reached around $2.3 billion. It also found that tax breaks amounting to around half a billion given by the states of Illinois and Kansas were also subsidies, although they did not cause harm to the EU. Washington "now finds itself with a crystal clear ruling that exposes its long-running multi-billion dollar subsidisation of Boeing through federal and state programmes as illegal," EU Trade Commissioner Karel De Gucht said in a statement released moments after the WTO announced its findings.

"These subsidies have resulted in substantial harm to EU interests, causing Airbus to lose sales, depress its aircraft prices and unfairly lose market share to Boeing," he said.

"The detrimental costs to EU industry from this lengthy and onerous subsidisation run into billions of euros." Airbus, part of the European Aeronautics Defence and Space Company (EADS), has claimed that illicit US subsidies caused $45 billion of lost civil airliner sales between 2001 and 2006. De Gucht said the EU was to "call on the US government to take the appropriate steps that may assist to achieve a mutually agreed solution to this dispute." However, the US government and Boeing claimed a moral victory, saying that the amount of illegal subsidies paid to the US aircraft maker was much less than that paid to European rival Airbus.

"Today a WTO panel confirmed what we have been saying for the last 20 years, that the WTO-inconsistent subsidies that the Europeans gave to Airbus dwarf anything that the US government has done for Boeing," US Trade Representative Ron Kirk said. Boeing claimed that the ruling "rejects 80 percent of the EU's claims against the US, finding no more than $2.7 billion of impermissible subsidies to Boeing not previously remedied." Boeing's calculations did not include a substantial chunk of federal tax breaks, which it said no longer applies because that particular programme has been scrapped. "Comparing today's decision with the decision last June (on the US complaint against Airbus) reveals a market distorted by Airbus' practices, with illegal launch aid being the key discriminator," said J. Michael Luttig, Boeing executive vice president and general counsel. A WTO ruling in June 2010 accepted three out of seven claims by Washington that Airbus effectively received illegal export subsidies. Both sides have appealed that ruling. Boeing said that the 2010 ruling faulted $1.5 billion in European R&D subsidies, $1.7 billion in infrastructure subsidies and $2.2 billion in equity injections. It also cited launch aid, which it claimed amounted to $15 billion. Analysts believe that both sides will eventually be obliged to restructure some state financing and strike an agreement to end the dispute after a lengthy and inconclusive battle.