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.

Honda's pressure to restructure Nissan is said to have been a key factor in the recent failed merger negotiations, according to leaks published Thursday by local media. Nissan, facing significant financial troubles,