Japanese carmakers Honda, Nissan and Mitsubishi have said they are dropping their talks to integrate their businesses.
They agreed to end their consideration of how to build a structure for the three brands to collaborate, their joint statement said.
Honda Motor Co and Nissan Motor Corp announced in December they would hold talks to set up a joint holding company.
Mitsubishi Motors Corp then said it was considering joining that group.
Analysts had been puzzled by what advantages any of the companies could gain because their existing models overlap.
Other details on why the talks unravelled were not immediately available.
Honda and Nissan initially said they were trying to finalise an agreement by June and set up the holding company by August.
The manufacturers will continue to work together on electric vehicles and smart cars, such as autonomous driving, they said on Thursday.
In recent weeks, Japanese media had various reports about the talks breaking down, citing unidentified sources.
Some said Nissan balked at becoming a minor player in the partnership with Honda, with Honda in a better financial position and tipped to take the lead in the joint executive team.
Nissan reported a loss for the July-September quarter as its vehicle sales sank, prompting it to slash 9,000 jobs.
At that time, chief executive Makoto Uchida took a 50% pay cut to take responsibility for the results.
