Together, Honda and Nissan would also pose more of a threat to Toyota Motor Corp., which is the world’s biggest automaker followed by Volkswagen AG.

Analysts questioned the timing of the Honda-Nissan potential deal amid intense competition from Chinese rivals, reported the news agency Reuters.

Two major Japanese automakers are heading for a historic merger, as Honda Motor Co. and Nissan Motor Co. signed a basic agreement to start full-fledged talks on integrating their businesses Monday. With the rise of electric vehicles manufactured by U.