Hiroto Saikawa has been appointed the new chief executive of Nissan after Carlos Ghosn last night stood aside.
Ghosn, who has stood at the company's helm for 16 years, will turn his focus to developing an alliance between Renault and Mitsubishi Motors.
The new appointment comes after years of speculation over when Ghosn would leave the top job amid investor concerns he was stretching himself too thin.
The change in leadership will make the best use of the greater scale that Mitsubishi brings to lower costs at a time when automakers are under pressure to expand and compete in new technologies such as self-driving cars, the company said.
Ghosn will continue as chairman of Nissan. He currently holds chairman positions at Renault and Mitsubishi as well.
Saikawa has been with Nissan for 40 years and has spent much of his career cost-cutting - much like Ghosn, whose reputation is for bringing Nissan back from years of losses and debt.
In 2013, Saikawa was appointed the company's chief competitive officer, and in November last year he became co-chief executive. He also heads Japan's auto industry lobby.