Shares in Air France-KLM plummeted today, a day after the Dutch government announced it was buying a stake in the troubled airline in a bid to match the French state's influence. 

The Franco-Dutch alliance's stock collapsed 11.3% to €11.29 shortly after the opening of the Paris CAC 40 exchange, which was down nearly 0.4%. 

France has reacted testily to the surprise Dutch purchase of the 12.68% share - which puts it on course to match France's own holding - saying that Air France-KLM must be free of "state interference". 

The Dutch swoop threatens to reignite tensions after a bitter dispute about the fate of the chief executive of the group's Dutch arm, and concerns over a series of strikes in France last year. 

"With this share purchase, the Dutch cabinet wants to be able to directly influence the future development of Air France-KLM in order to optimally ensure the Dutch public interest," Dutch Finance Minister Wopke Hoekstra said. 

The move stunned Paris, with Economy Minister Bruno Le Maire saying the Dutch government had not informed the French state.

"It is essential to respect the principles of good governance and for Air France-KLM to be managed... without state interference," Le Maire said. 

Air France and KLM merged in 2004 but continue to operate largely separately, while the French arm in particular has struggled with industrial action in recent years.

French Budget Minister Gerald Darmanin today called on states to interfere in the company as little as possible. 

"We must have good relations with our friends from the Netherlands," Darmanin told Europe 1 radio. 

"It is especially necessary that the states are involved as little as possible in the running of a large company like this," he said.

"We must let the people of Air France-KLM work," he added.