* Working group to evaluate options, report in June
* To consider role of developing countries
* Under pressure to find alternative to EU scheme (Adds quote, link to Airbus story)
By Allison Martell
March 15 (Reuters) - The question of what role developing countries should play in reducing carbon emissions threatened to derail discussions at a top-level meeting of the United Nations body that oversees civil aviation, according to one official who attended Wednesday's meeting.
The official, who asked not to be identified because he is not authorized to speak to the media, said the idea of "common but differentiated responsibility" was a point of conflict in four hours of debate at the governing council meeting of the International Civil Aviation Organization.
The concept of differentiated responsibility argues that developed countries should shoulder most of the burden for cutting emissions.
The news came as sources said China was suspending the purchase of 10 more Airbus jets, escalating a trade row over airline emissions.
In a decision obtained by Reuters, the council instructed a working group to continue its study of "market-based measures" to deal with aviation emissions and report back at the next council meeting, scheduled for June.
It also asked the working group to evaluate whether the measures being studied can "accommodate the special circumstances and respective capabilities of developing countries".
The official said a large majority of the council voted for the decision, including China, Russia, the United States, and the European members.
Montreal-based ICAO was thrust into the spotlight last year after the European Union agreed on controversial new rules to limit airline carbon emissions.
The EU rules, which took effect Jan. 1, mean that all airlines that use EU airports must pay into a carbon offset program. That stirred threats of an international trade war with the potential to disrupt global air traffic.
A coalition of more than 20 countries, including China, Russia and the United States, has been organized to oppose the EU scheme, arguing the plan infringes on their sovereignty. In February the group met in Moscow to discuss tactics.
"The good news is that ICAO is pressing on with its analysis of options. The timing is ambitious. (Common but differentiated responsibility) is certain to come up," said Bill Hemmings, program manager of environmental lobby group Transport & Environment. "It's not insurmountable."
Late in 2011, ICAO said it would accelerate its hunt for a global alternative to the EU measures. It aims to have a draft proposal by the end of 2012.
An ICAO spokesman said in December that the basic options under consideration are some form of emissions trading, fuel-based carbon levies, levies on departing passengers and cargo, and carbon offsetting.
The European Commission has said it was forced to act alone after ICAO failed to come up with a viable plan. It said it will modify its law if the ICAO comes up with an acceptable alternative. (Additional reporting by Barbara Lewis in Brussels; Editing by Janet Guttsman and Peter Galloway)