The chief executive of loss-making Alitalia has stepped down as the airline announced deeper annual losses.

The carrier said Andrea Ragnetti had resigned from his position and “until a new chief executive is appointed the board had given the position in the interim to chairman Roberto Colaninno”.

The exit of Ragnetti comes as speculation grows about whether the airline can remain independent as losses mount and it continues to lose share to budget carriers and Europe’s high-speed trains.

The resignation came as the airline announced a €280 million net loss, compared with a loss of €69 million in 2011. Passenger numbers fell slightly to 24.3 million.

The Financial Times reported that it was thought that 25% shareholder Air France-KLM would seek to increase its stake – but this was denied by “people close to Alitalia and Ragnetti”.

The French-Dutch group was thwarted in its attempts to take over the Italian airline in 2008 after opposition from unions and the then-government of Silvio Berlusconi.

Air France-KLM bought its quarter share in Alitalia for €300 million in 2009.

Analysts have suggested that it was likely that some of the consortium of 21 Italian investors, which took over the bankrupt airline at the end of 2008, would sell part of their shareholdings to Air France-KLM after the lock-up period expired.