In September 2008, Air Berlin confirmed merger talks with competitor TUIfly, but added it was speaking with all parties. Air Berlin had, until 2007, been flying many code-share TUI flights. At the end of March 2009, Air Berlin PLC and TUI Travel PLC signed a deal by which their German flight businesses were to operate a long-term strategic alliance. Originally, each company was to take a 19.9% stake in the other and the German cartel authorities were petitioned for approval. After the Bundeskartellamt expressed concerns, the cross-ownership plan was not implemented. Instead, TUI Travel PLC purchased a 9.9% stake in Air Berlin PLC using a capital increase at a subsidiary to do so.