Air Berlin has suffered losses last year, according to estimations made yesterday evening (Weds).The airline, which cooperates with Austrias FlyNiki, announced its could have suffered operative losses “of a one-digit million-Euro sum”. Air Berlin explained the extreme winter weather in November and December and the strike of air traffic controllers in Spain last month were the major reasons for the negative development. The company had to cancel around 800 flights around Christmas when several airports across Europe were forced to stop operating due to strong snowfall.Air Berlin said it will present detailed figures for 2010 next March. The Berlin-based carrier previously said it saw chances to improve its 2009 earnings before interest and taxes (Ebit) of 28.5 million Euros in 2010.The aviation firm which is Germanys second-biggest airline after Austrian Airlines (AUA) owner Lufthansa said earlier this month it registered 33.6 million customers last year. Air Berlin stressed this was a 3.8 per cent improvement to the year.This announcement surprised many market experts since Air Berlin had to call off 3,500 flights following the eruption of Icelandic volcano Eyjafjallajokull and the ensuing ash cloud that had covered vast parts of Europe for weeks in the first half of 2010.Air Berlin is headed by Joachim Hunold. The carrier, which has more than 8,000 employees, increased its interest in FlyNiki by 25.9 per cent to 49.9 per cent in February 2010. FlyNiki boss Niki Lauda stressed at that time that his airline will remain Austrian although the agreement features a clause giving Air Berlin the option to take over its Austrian cooperation partner in full.Air Berlin and FlyNiki started cooperating as far as their schedules and marketing efforts are concerned in 2006.News that Air Berlin may have suffered substantial losses last year comes days after FlyNiki confirmed reports suggesting that it has plans to team up with Dubai-based aviation giant Emirates.FlyNiki official told Austrian business dailies the Vienna-based firm was considering reaching a deal involving connection flights. Lenz said the companies could imagine setting up a partnership in which flights will be handled under a joint code-sharing agreement.Emirates was established in 1985. It is one of the biggest and fastest-growing aviation firms in the world.