The EU proposed extending the exemption, which was set to end at the start of 2017, on Friday to avoid a repeat of tensions when it tried to include all flights in 2012.

But it was immediately criticised by environmental campaigners who oppose an International Civil Aviation Organization (ICAO) deal struck in October on a global market-based measure for offsetting airline emissions.

Airlines who back the ICAO deal, which will not be mandatory until 2027, welcomed the EU proposal as they want to avoid a patchwork of national and regional schemes.

ICAO's deal was seen as not being ambitious enough by the European Parliament, which along with member states, will have to approve the EU exemption proposal.

It will also be reviewed by the European Commission as details on the implementation of the UN scheme become clear.

The fate of the emissions trading system (ETS) covering flights within Europe will also be assessed in the review, EU officials said, adding that all options were on the table, including dismantling it once the global system is in place to avoid double counting for flights within the bloc.

"The European Union is now focused on getting the global scheme up and running. We are serious about achieving carbon neutral growth for aviation worldwide, and we will provide technical support to make it happen," Violeta Bulc, the EU's transport commissioner, said.

The EU had ordered carriers to buy credits for foreign flights under its ETS in 2012 but backtracked when countries said it violated their sovereignty and China threatened to cancel plane orders from Airbus Group (>> Airbus Group).

Airlines for Europe (A4E) which represents Ryanair (>> Ryanair Holdings plc), easyJet (>> easyJet plc), Lufthansa (>> Deutsche Lufthansa AG), Air France KLM (>> Air France-KLM) and British Airways owner International Airlines Group (>> International Consolidated Airlns Grp SA), and others said it expected the ICAO scheme to be the only measure for tackling carbon emissions within the bloc as of 2021.

"This proposal provides certainty for European operators enabling them to focus their efforts on the implementation of the global deal to effectively tackle climate change," Thomas Reynaert, A4E’s Managing Director, said.

Under the ETS emissions are capped, whereas the ICAO deal allows carriers to increase them without limit as long as they offset them with carbon credits from environmental projects.

Aviation, which produces about 2 percent of carbon dioxide emissions, was excluded from the Paris accord to fight climate change, and environmental groups say the ICAO deal is not compatible with accord's aim to limit temperature increases.

"The Commission has chosen to again suspend the only effective measure to regulate aviation emissions, all for a voluntary deal which is years from coming into operation and which may never actually reduce the climate impact of flying," Bill Hemmings, aviation director at Transport & Environment, said.

(Editing by Alexander Smith)

By Julia Fioretti