TOKYO — Nissan is set to call off merger talks with rival Honda, a source said Wednesday, abandoning a $60 billion-plus tie-up that would have created the world's No. 3 automaker and raising questions about how it will drive a turnaround by itself.

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.

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.