Renault executives also insist they have an accurate reading on Nissan's business, including its debts.

But in recent weeks, it gave Renault executives answers that Renault considered satisfactory.

Another senior Renault executive on assignment at Nissan, Thierry Moulonguet, will become Nissan's chief financial officer as part of a broader management shake-up, the companies said.

But Renault executives in Paris say that is not what they have in mind.

"Today, Europe is a price market," said Stéphane Lemperier, a Renault executive, where consumers buy based on low prices.

On 16 November, militants broke into the home of a Renault executive in Córdoba and took him hostage.

He was quickly followed by 40 more Renault executives, who made it evident that they were in charge.

Given the slim margins and deep losses at many car companies, most would be thrilled with an 8 percent operating margin, Mr. Ghosn and other Renault executives said.

Renault executives see other potential benefits.

Renault executives also say they will bring some flare and excitement to Nissan's staid line.