Nissan declined to comment on the changes at Renault.

Renault and Nissan need each other to thrive in the future, executives have insisted. Only by combining forces can they afford the large investments they need to make in autonomous driving and other technology to avoid being outpaced by competitors. And Renault needs Nissan, the dominant performer, to continue contributing to Renault financially as its performance slips in Europe.

The French state, which owns a 15 percent stake in Renault, has been eager to get the relationship with Nissan back on track and supported Mr. Senard’s decision to start looking for a replacement. France’s finance minister, Bruno Le Maire, said this week that he had full confidence in Mr. Senard “to choose with the board the best governance.”

Nissan in particular has been torn by internal inquiries that recently revealed improper payments to several top executives, including two of the insiders who brought down Mr. Ghosn. As part of those investigations, Mr. Saikawa resigned on Sept. 9 after admitting that he had received about $440,000 in improper share-based compensation.

Mr. Bolloré had earlier been hailed by Renault after being thrust abruptly into the role of chief executive in January, the same time Mr. Senard was hired from the French tire maker Michelin to quickly fill the vacuum left by Mr. Ghosn.

Yet executives have been concerned by Renault’s worsening finances. Its revenues fell 6.4 percent in the first half of 2019 from a year earlier, while operating profit slumped 11.8 percent, prompting Renault to cut its sales targets for the full year.

In his interview with Les Échos, Mr. Bolloré said the move was “all the more inexplicable because Renault is one of the very few car manufacturers that have not made a profit warning despite the sectoral crisis we are facing.”

Renault, which owns 43 percent of Nissan, can ill afford to see its performance slide further while Nissan is also grappling with a sharp drop in profits amid plunging sales. Nissan recently announced plans to lay off as many as 12,500 employees worldwide.