"You don't change into a secular regime just like that," Total Chief Executive Patrick Pouyanne told an event in London.

While most of Saudi Arabia's young population, roughly 70 percent of the total, support the reforms, the older generation might be reluctant to accept such changes, he said.

"I am supportive of this reformist spirit, even if it is difficult to be optimistic or pessimistic at that stage. Major changes are not always easy to implement and can take time," Pouyanne told Reuters after his initial remarks.

At Thursday's event, Pouyanne was asked if Prince Mohammed was a reformist like former Soviet President Mikhail Gorbachev, who was stripped of power in 1991 in a coup led by communist party conservatives and left jobless the same year by the collapse of the Soviet Union.

"Do you remember what happened to (Mikhail) Gorbachev?” Pouyanne responded. "As you remember chaos came before stabilisation happened.”

Total is one of the most active and biggest investors in the Middle East. It has a major refining site in Saudi Arabia, large concessions with the UAE and Qatar and this year it signed a deal to develop part of Iran's South Pars, the world's largest gas field.

"Total is perceived in most of those countries as representing France. We benefit, even if we are a commercial company, from this position of France. Total has a nationality and that nationality is a strength in the oil and gas business."

(Reporting by Ron Bousso and Dmitry Zhdannikov; Editing by Susan Fenton and Edmund Blair)