Carlos Ghosn's arrest brings Nissan-Renault rivalry into the open

Ghosn, who was among the best-paid executives in both France and Japan, stands accused of under-reporting income of about $44 million

Tensions between Nissan Motor Co. and Renault SA over the future of their car-making partnership have exploded into the open as the downfall of Chairman Carlos Ghosn roils the automotive industry and his top lieutenant, Hiroto Saikawa, moves to consolidate power in his absence.

The two companies, which are connected via a complex structure of cross-shareholdings and joint manufacturing, have drastically differed in their reactions to Ghosn’s arrest in Japan on suspicion of financial offenses.

Tuesday night in Paris, Renault’s board stopped short of firing the French-Brazilian executive, and asked Nissan to hand over details of his alleged misdeeds. Nissan, by contrast,