Aegean Airlines SA (, ; ) is the largest Greek airline by total number of passengers carried, by number of destinations served and by fleet size. A Star Alliance member since June 2010, it operates scheduled and charter services from Athens and Thessaloniki to other major Greek destinations as well as to a number of European destinations. Its main hub is Athens International Airport in Athens, with a secondary hub at Thessaloniki International Airport. It also uses six other Greek airports as seasonal bases during the summer. It has its head office in Kifisia, a suburb of Athens. In 2009, it carried 6,600,000 passengers surpassing for the first time its rival Olympic Airlines, which carried 5,265,729 passengers. In 2010 Aegean Airlines carried 6,100,000 passengers, of which 50% were foreigners. On 21 October 2012 Aegean Airlines announced that it had struck a deal to acquire Olympic Air, pending approval by the European Commission.