PARIS — Nearly a year after the arrest of Carlos Ghosn, Renault, Nissan and Mitsubishi are moving to reboot the world’s largest auto alliance by appointing a general secretary at the top of their partnership in a move it hopes will accelerate business.

The structure, announced by the companies Friday, is a marked change from the way Mr. Ghosn ran the automakers as a single chieftain calling most of the shots, toward more consensus-based decision-making by the heads of the three companies.

The restructuring comes as Renault, Nissan and Mitsubishi, which together sold more cars than any other company in 2018, struggle to improve profitability in the face of sweeping changes transforming the industry, including the rush to electric vehicles. All three companies have reported a steep decline in sales worldwide, and face fresh challenges as other automakers join forces to generate efficiencies in an increasingly tough global market.

The general secretary, whose name will be announced next week, will “coordinate and lead important programs to enhance the efficiency of the alliance,” the groups said in a statement Friday.