Air France shares went into a tailspin on the Paris stock exchange on Monday after the resignation of the strike-hit company's CEO.

Air France-KLM boss Jean-Marc Janaillac announced his resignation Friday after staff at the carrier's French operations rejected a pay deal aimed at ending months of walkouts.

Janaillac, who had been in the post for under two years and staked his future at the company on staff accepting the deal, deplored their decision as a "huge waste".

In early bourse business Air France stock was down nearly 13 percent at 7.08 euros.

Staff and management at the carrier have been locked in a dispute over pay since February.

Intermittent strikes in recent weeks have prompted the cancellation of a quarter of flights on average.

Unionised staff are set to walk out for the 14th day on Monday as they press for a 5.1-percent salary increase this year as the company recovers from years of losses and restructuring.

France's economy minister on Sunday warned that the survival of Air France was now in the balance.

"I call on everyone to be responsible: crew, ground staff, and pilots who are asking for unjustified pay hikes," Economy Minister Bruno Le Maire told the BFM news channel.

"Be responsible. The survival of Air France is in the balance," he added.

He warned that the state, which owns 14.3 percent of the group, would not serve as a backstop.

"Air France will disappear if it does not make the necessary efforts to be competitive," he warned.