All three firms Renault, Nissan and Mitsubishi were struggling even before the coronavirus pandemic, which has caused sales to plunge.
The strategy presented on Wednesday aims at improving the competitiveness and profitability of the three companies by developing nearly half of cars jointly by 2025.
"The plan will bring out the most of each company's assets and performing capabilities, while building on their respective cultures and legacies," said Renault head Jean-Dominique Senard, who also leads their alliance.
It will also increase "their respective competitiveness, sustainable profitability and social and environmental responsibility," he added.
Renault is expected on Friday to announce a 2 billion euros savings plan which could see thousands of job cuts in four French sites by 2024.
The plan "is expected to deliver model investment reductions of up to 40 percent for vehicles fully under the scheme," a joint statement said.
The carmakers will adopt a "leader-follower scheme to enhance efficiency and competitiveness" while also letting one take the lead in each region of the world.
The alliance will focus on one model per product segment, which would be developed by the leading company in that particular segment and adapted by the others.
The carmakers will also focus on their core regions "with the aim to be among the most competitive and to serve as a reference for the others to enhance their competitiveness," said the statement.
Nissan will be the reference for China, North America and Japan; Renault in Europe, Russia, South America and North Africa; and Mitsubishi Motors in ASEAN and Oceania countries.
