With interests ranging from cutting-edge jets and industrial design software to wine and an auction house, Dassault's family company holds outsize influence, not least given its key role as a pillar of France's defence strategy.

Yet although he took the reins from his father, Dassault pointedly did not designate a family heir among his own four children, who all sit on the holding company's board.

"There won't be any arguments among his inheritors," Olivier Dassault, a lawmaker for the Oise region near Paris, told Europe 1 radio on Tuesday following his father's death on Monday.

"In any case that is the promise I can make today before you, my brothers and sisters, and all French citizens," he said.

Olivier Dassault's brother Laurent oversees the family holding company's investments, while another brother, Thierry, has specialised in economic intelligence, the rightwing Figaro newspaper -- also a family holding -- wrote in a homage to Dassault on Tuesday.

Their sister Marie-Helene, who focuses on philanthropy, was named head of the holding company's board this year.

The four siblings have equal stakes in the holding company, but that hasn't avoided frictions -- Olivier once declared himself "the most qualified" to take his father's place, earning a stern public rebuke from his father.

- 'He prepared for this' -

Officially Serge Dassault will be succeeded by his right-hand man Charles Edelstenne, 80 years old and a former head of Dassault Aviation, the family's crown jewel.

"Unlike his own father, he prepared for this," said Claude Carlier, a historian who has written extensively on Serge and his father Marcel.

And Edelstenne hand-picked Eric Trappier as his successor at the plane maker in 2013, though analysts expect that like Dassault, Edelstenne is unlikely to be a passive observer at any of the family's companies.

"Today we have a president of our group who was designated well before my father's death, whom we voted for unanimously," Olivier Dassault said of Edelstenne.

But French media reports have often alluded to tensions within the family, notably the father's supposed disappointment that none of his children obtained an engineering degree as he did -- at France's elite Polytechnique school.

According to French magazine Challenges, a succession plan laid out in 2009 stipulates that no shares in the holding company can be sold to anyone other than direct Dassault descendants for the ten years following the deaths of Serge and his wife Nicole, who is four years his junior.

Yet it is unclear if their children will share their father's passions for planes, new technologies, the press and the Chateau Dassault vineyard in Bordeaux.

In any case, they will be closely watched by the French government since Dassault planes are core to the country's nuclear dissuasion policy as well as its overall military independence.

In 2014 it signed an accord with the holding company making the state "the guardian of the temple", effectively giving it a say on any shareholder shake-ups.

"Dassault Aviation is an integral part of France's pursuit of strategic autonomy," said Olivier Zajec, a defence specialist at Lyon III university in southeast France.

"It's also a question of the future of air power," Zajec said, in particular Dassault's role in developing a French-British combat drone for 2030, and a French-German combat jet set to enter service by 2040.

Dassault Aviation is also the main shareholder in French defence and arms group Thales, holding 25 percent alongside the state's 26 percent.

"It's not a matter of who will be number one, number two or number three," Olivier Dassault said.

"It's a matter of pursuing my grandfather's work, my father's work."

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