Berlin\'s new airport will probably not open before March 2013 because of problems with fire regulations, sources said on Wednesday, further embarrassing authorities who had predicted a three-month delay from the original date of June 3. The capital\'s long-awaited new airport will replace Tegel and Schoenefeld airports, both dating from the Cold War era. Just weeks before its opening date the operators said the Berlin-Brandenburg airport would not be ready in time. \"It looks like March 2013,\" government sources told Reuters, requesting anonymity. The opening of what will be Germany\'s third largest airport after Frankfurt and Munich has been postponed once already. Keeping open the two older airports will cost about 15 million euros ($19.5 million) a month and airlines that have been selling tickets for flights from Berlin-Brandenburg for months face additional costs. The 2.5 billion euro new airport initially aims to attract up to 27 million passengers a year, making it about half the size of Germany\'s main airport in Frankfurt and less than a third the size of the world\'s busiest airport in Atlanta. Bild newspaper earlier cited a letter from a building regulation agency to the new airport\'s technical chief, Manfred Koertgen, warning that any interim safety measures would not be enough to secure approval. \"We won\'t be able to get a fully automatic system in place that quickly. That rules out an opening this year,\" an airport official told the paper. It would then make most sense to open the airport when airlines introduce their summer 2013 flight plan from end-March next year, the official quoted by Bild said. A spokesman for the airport declined to comment but noted that the Berlin-Brandenburg supervisory board was meeting later on Wednesday. \"We expect that the board meeting will result in a time plan,\" he said. One of the new airport\'s first challenges was to have been handling travellers going to the Euro soccer championship next month in Poland and Ukraine. A spokesman for national carrier Lufthansa said: \"The airport should only be opened if stable and safe flight operations can be provided. It would be a bigger catastrophe if a new date was named now that would have to be postponed again.\" Germany\'s second largest carrier, Air Berlin, said it expected a decision during the day. CEO Hartmut Mehdorn said on Tuesday it made sense for the airport opening to coincide with the start of the winter schedule. (Reporting by Maria Sheahan and Victoria Bryan in Frankfurt; Writing by Alexandra Hudson; Edited by Stephen Brown and Tim Pearce)