Shares in Air France fell 14% in early Monday trading, reacting to the latest events at the troubled airline.
It was the first chance investors had had to respond to chief executive Jean-Marc Janaillac’s resignation and comments by France’s economy minister.
Mr Janaillac’s move came after staff at the loss-making airline rejected a new pay deal and continued their industrial action in pursuit of a 5.1% pay rise.
And on Sunday, minister Bruno Le Maire warned Air France could “disappear”.
The French government owns 14.3% of the Air France-KLM parent group.
Monday’s walk-out is the 14th day of action.
Despite the strike, the airline insisted that it would be able to maintain 99% of long-haul flights on Monday, 80% of medium-haul services and 87% of short-haul flights.
The government’s response is seen as a test of labour reforms launched by French President Emmanuel Macron. There have also been strikes at the state-owned SNCF rail company.
Mr Le Maire told French news channel BFM TV: “I call on everyone to be responsible: crew, ground staff, and pilots who are asking for unjustified pay hikes.
“The survival of Air France is in the balance,” he said, adding that the state would not serve as a backstop for the airline’s debts.
“Air France will disappear if it does not make the necessary efforts to be competitive,” he warned.
Air France-KLM reported a net loss of €269m (£238m) in the first quarter of the year.
British Airways and Lufthansa have already undergone heavy cost-cutting in recent years, amid rising competition from low-cost airlines and carriers from the Gulf states.
But many analysts say Air France has lagged far behind in restructuring and has failed to address its continued losses.
The group has already downgraded expectations of its financial performance for 2018.
Air France merged with Dutch carrier KLM in 2004. The joint company flies tens of millions of passengers around the world every year.