Airlines will receive allowances to emit almost 213 million tonnes of carbon dioxide when the aviation sector is included in the European Union's emissions trading scheme (ETS) from 2012.
The European Commission said that, based on average annual aviation emissions from 2004-06, it had calculated the number of available allowances for 2012 to be just shy of 213 million tonnes. This represents 97% of the 2004-06 emissions figure.
From 2013, the aviation sector will have access to 208.5 million tonnes of carbon dioxide permits each year. This represents 95% of the historic emissions data from 2004-06.
The EC originally said 85% of this allowance would be handed out free, with the remaining 15% subject to auction.
However, this is not set in stone and a firm decision will be announced later this year.
"Emissions from aviation are growing faster than from any other sector, and all forecasts indicate they will continue to do so under business-as-usual conditions," says European commissioner for climate action Connie Hedegaard.
"By publishing the data on which allocations will be based, we prepare for the full inclusion of aviation in the emissions trading system," she adds.