Carlos Ghosn has handed over the day-to-day running of Nissan Motor Co. to Hiroto Saikawa, who will take the mantle of president and CEO while his longtime boss focuses on revamping struggling affiliate Mitsubishi Motors Corp.

Ghosn, 62, will remain chairman of Nissan, a title he also holds at alliance partners Renault SA and Mitsubishi Motors. He'll stay as CEO of Renault as the transformation of the French carmaker isn't finished, he said in an interview, with the current midterm plan ending in 2018. Saikawa will assume charge April 1.

"There's a point in time where you have to be realistic about how much things you do and you can do well. This is the trigger," Ghosn said at Nissan's headquarters in Yokohama on Thursday. "There's a moment when you have to pass the baton to someone else. I've always said I would love to have a Japanese to be my successor and Saikawa-san is somebody I have been grooming for many years."