Nissan Motor Co. is seeking a new partner as it prepares to end negotiations to form a joint holding company with Honda Motor Co., people familiar with the matter said.

There's strife of the horizon as Nissan vehemently opposes Honda's suggestion of making the struggling carmaker its subsidiary.

The reality is that Nissan would effectively become a subsidiary of Honda, something the company is finding hard to swallow. Mitsubishi Motors, a much smaller vehicle manufacturer, has already indicated that it will decline an invitation to participate in the merger so as not to lose managerial independence.