At a glittering ceremony, attended by representatives from across the travel industry, the German carrier picked up the Best Short-Haul Airline award, ahead of rivals British Airways and bmi.
Voted for by business travel buyers and leading business travel journalists, the awards honour excellence in the corporate travel industry and recognised Air Berlin’s commitment to the sector.
Titus Johnson, Air Berlin country manager for the UK and Ireland, said: "This is a great way to start 2010.
"Air Berlin has carved out an enviable reputation amongst corporate clients. With pressure on travel budgets we are the ideal partner, offering an unbeatable combination of lower fares while maintaining the on-board frills such as food and drink."
Air Berlin won the same prize in 2007 at the event's predecessor, the Business Travel World Awards.
Nick Barton, Stansted Airport’s Commercial and Development Director, said: "On behalf of everyone at Stansted, I'd like to offer congratulations to Air Berlin.
"They've enjoyed great success with the growth and development of their business at Stansted and this success has been now officially recognised by the business industry through these coveted awards."