Just eight Chinese airlines and two Indian carriers failed to submit carbon emissions data before a 31 March deadline stipulated in the Emissions Trading Scheme (ETS), EU climate commissioner Connie Hedegaard has said.
With more than 1,200 international carriers adhering to the deadline, the revelation suggests efforts spearheaded by China, India and Russia to oppose the carbon trading system are faltering.
"We have given them until mid-June to report back their data," Hedegaard said of the ten unidentified airlines that did not report emissions figures.
Under the terms of the ETS, airlines must from 2012 onwards declare carbon emissions data for any flights landing in or taking off from EU territory. Annual figures are then set against company-specific quotas determined by Brussels, and carriers must pay for surplus emissions by purchasing carbon permits on the free market.
Though opposition to the ETS remains widespread - with more than 20 countries attending a "coalition of the unwilling" conference in Moscow last February - the scheme's detractors appear to have been swayed by EU threats of punitive measures for non-compliance.
Penalties for boycotting the ETS start at €100 ($128) per tonne of carbon, and repeat offenders can ultimately be banned from EU airspace.
The Chinese government prohibited its airlines from participating in the cap-and-trade scheme earlier this year, while India and Russia talked up the prospects of a global trade war if foreign carriers were included in the system. Opponents view it as an extra-territorial tax which violates international treaties like the Chicago Convention.
But the EU Court of Justice overturned legal challenges to the ETS in December 2011, concluding that Brussels was acting within the constraints of European law.
Hedegaard said the EU will now redouble efforts to establish a global carbon trading system under the auspices of the International Civil Aviation Administration (ICAO). All sides of the dispute view an ICAO solution as the best way forward, though the EU says the UN body has dragged its feet over implementation of a wider scheme.