The European Commission (EC) has delayed, for the second time, the formal announcement of its baseline aviation sector CO2 emissions standard until mid-2010, Bloomberg reported.

The EC had originally set a 2 August 2009 deadline for publishing a CO2 baseline necessary for its emissions cap for flights into and out of the EU and its related Emissions Trading Scheme, both of which are scheduled to come into effect in 2012.

The Commission postponed the date after Europe’s main airline associations voiced concern over methodology and the accuracy of the data used to calculate the average annual sector emissions of the years 2004, 2005 and 2006.