German aviation giant Lufthansa has offered concessions to encourage the European Commission to green-light its planned purchase of parts of bankrupt Air Berlin, the Brussels authority told AFP.

"We have received remedies" from Lufthansa concerning the case, a spokesman said.

As Europe's highest competition authority, the Commission is examining the impact the German group's plans would have on the continent's aviation market.

Now that Lufthansa has submitted more extensive concessions, the deadline for Brussels to reach a decision has been pushed back from December 7 to December 21, the spokesman added.

The group itself was not immediately available for comment when contacted by AFP.