Paris - French-Dutch airline Air France-KLM said Thursday it had deposed a formal complaint at the European Commission over the sale of Austrian Airlines to the German carrier Lufthansa.

"The agreement concluded on December 5, 2008, between Austrian authorities and Lufthansa does not conform to the conditions that were imposed on Air France-KLM during the procedure of choosing a strategic partner (for Austrian Airlines)," the company said in a press statement.

On December 5, Lufthansa signed a deal in Vienna to buy 41.65 per cent of Austrian Airlines from Austria's state holding OeIAG for the token price of 366,000 euros (465,000 dollars), creating Europe's biggest airline.

The German carrier plans to take over 100 per cent of Austrian Airlines, first through the privatization, and then through buying free-floating shares.

The deal, Air France-KLM said, was predicated on the cancellation of a debt of 500 million euros by the Austrian government and a per- share price that was far below market value.

Air France-KLM said the deal was "not conducted in the best interest of the concerned parties or according to the normal market price," and called for a thorough investigation by the European Commission.

The closing of the deal still depends on approval from the European Commission, which is expected by the spring. (dpa)