German carrier Lufthansa and Swiss International Air Lines are set to merge after the European Commission on Tuesday approved Lufthansa’s acquisition of Swiss, in a further consolidation of European airlines.

But the commission said that the purchase was dependent on the parties surrendering take-off and landing slots notably at Zurich and Frankfurt airports, and other concessions.

"In light of these commitments, the commission has concluded that the transaction would not significantly impede effective competition," said the commission, the executive which regulates competition in the 25 member states.

Lufthansa has said it wants to acquire Swiss to expand its international network and boost its competitive position in Europe.

The purchase, which cost Lufthansa up to 310 million euros (370 million dollars), is the second-biggest merger in the European aviation sector following that of Air France and KLM a year ago.

Germany’s flag carrier signed a deal on March 22 to take over its ailing Swiss counterpart, which was created after Swissair collapsed in 2001.

Swiss has since faced huge financial problems, battered largely by the unrelenting rise in low-cost airlines around Europe.