Nissan Motor Co. could find itself chained to a much bigger gorilla as Renault SA and Fiat Chrysler Automobiles NV proceed with a plan to forge closer ties. The Japanese carmaker doesn¡¯t like it but may not have much of a choice.

Fiat Chrysler announced a merger plan Monday with Renault, Nissan¡¯s partner of two decades, that could create the world¡¯s third-biggest automaker. While the pair isn¡¯t seeking a merger with Nissan for now, they plan to eventually invite Nissan and Mitsubishi Motors Corp., Renault¡¯s existing global alliance partners, to join forces, sources said.

Nissan isn¡¯t involved in talks between the two European car companies and doesn¡¯t view an extensive deal between them as a positive development, people with knowledge of the matter said. Nissan isn¡¯t interested in a scenario that pursues car sales for the sake of volume, the sources said, asking not to be identified because Nissan¡¯s stance isn¡¯t public.