Air Berlin's entry into the Oneworld alliance will confirm its status as a serious business airline, its UK and Ireland general manager Titus Johnson believes.
The German carrier enters the alliance a few months before the 2012 Olympics and weeks before Berlin Brandenburg International airport opens in June that year.
BBI is currently under construction on the site of the existing Berlin Schonefeld airport and has ambitions to rival Frankfurt as a hub, at which Lufthansa and the Star Alliance carriers dominate, when it is completed.
"Air Berlin will be the biggest carrier at BBI when it opens," said Johnson.
"We have a share of the domestic market of more than 40%. As a home carrier we bring oneworld a very big player in Germany with a high number of connecting opportunities at BBI."
Air Berlin, a hybrid carrier that evolved by offering on board frills but with budget fares, is now Germany's second largest and Europe's fifth biggest airline, carrying 28 million passengers.
Air Berlin already serves more German cities than any other and it will easily outstrip Lufthansa's presence at BBI, which will handle 45 million passengers, although the new airport, at its peak, will fall far short of an expanded Frankfurt airport, which plans to accommodate 88 million passengers by 2020.
Air Berlin may not have appeared an obvious choice for the American Airlines and British Airways-dominated oneworld, but the spread of domestic connections in Germany, Europe's strongest economy, made the carrier attractive to the alliance.
Air Berlin's long-haul network includes routes from Germany to Los Angeles, New York JFK and Miami, three important oneworld hubs.
The carrier brings the alliance 75 new gateways and, as well as Berlin, hubs at Dusseldorf, Munich and Nuremberg plus 165 aircraft, including a long-haul fleet of 13.
Air Berlin already has code share agreements with Bangkok Airways and Russia's S7, another prospective oneworld member, on some routes.
The announcement that Air Berlin was also a prospective oneworld member was swiftly followed by the signing of code share deals with American Airlines and fellow alliance member Finnair, which gives Air Berlin passengers access to the Finnish carrier's Asian flights via Helsinki.
Air Berlin's own destination mix is as diverse as Spain, Thailand and Iraq, although from the UK it currently only offers five German routes including its main hubs.
After previously dabbling in UK domestic services and Spanish routes, Air Berlin has consolidated its UK operation from Stansted and Manchester more towards the business traveller.
Air Berlin already boasts more than 1,000 corporate agreements, web and SMS check-in, a frequent flier scheme plus a point system for SME customers and is sold via all the GDSs.
"Air Berlin has evolved into a quality full-service airline over the last few years," said Johnson.
"Particularly during the recession we gained enormous traction with companies with which we would not have been on the radar before. The only thing we don't offer in short-haul is a lounge and a two-class cabin."