TOKYO -- Nissan Motor's turnaround efforts suffered a heavy blow as Jun Seki, who assumed one of the automaker's three new leadership posts just a month ago, will leave the company to join Japanese motor maker Nidec as early as February, Nikkei learned on Tuesday.
Seki is seen as a potential candidate to become Nidec's next president.
Nissan officially announced Seki's resignation on Wednesday without revealing the date of his departure or his successor.
The automaker's shares plunged on the news, dropping 2.91% at one point to a year-to-day low.
Seki, who became Nissan's vice chief operating officer, the No. 3, at the beginning of December, played a leading role under former CEO Hiroto Saikawa in crafting the company's rebuilding plan, announced in July.
Seki formed a new tripartite team of top executives at Nissan, together with President and CEO Makoto Uchida and Chief Operating Officer Ashwani Gupta. The automaker sought to divide power and avoid another authoritarian management structure like the one under Carlos Ghosn, the former chairman now facing criminal charges.
After taking the helm of the company, the three men held their inaugural news conference Dec. 2, vowing to push forward reforms.
"Right now, there is an enormous gap between employees on the front line and management," Seki said. "In order to narrow the gap as much as possible, I will endeavor for improvement alongside Mr. Uchida and Mr. Gupta."
Seki's swift departure for Nidec likely will damage Nissan's improvement plan, as the automaker remains unable to form the stable management needed to revive its distressed earnings and solve its governance problems.
Seki is the sole person among the three new leaders who worked his way up through Nissan. Uchida hailed from Nissho Iwai, the predecessor to Japanese trading house Sojitz. Gupta is a Renault man, the French automaker that leads a strained alliance with Nissan.
Seki's role under Saikawa's brief reign as Nissan's No. 1 also makes him the most informed of Nissan's management among the triumvirate. Uchida was in China at the time, while Gupta was working at alliance partner Mitsubishi Motors as chief operating officer.
But Seki's position as Saikawa's deputy worked against him during the company's search for the new CEO. "There is no large change from Saikawa's management," said a member of the nominating committee, made up of outside directors.
The 58-year-old executive's decision to leave was likely related to the realization that he would not one day become CEO even if he stayed. Uchida, the new CEO, is five years Seki's junior, as well as Seki's successor of Nissan's operations in China.
There is also speculation that Seki may have had differing views toward Nissan's relationship with Renault from Uchida and Gupta. Saikawa, who Seki had closely supported, had openly opposed the idea of merging with the French automaker.
Meanwhile at Nidec, Chairman and CEO Shigenobu Nagamori has led Nidec since founding it in 1973, and finding his replacement has become a serious issue.
Nagamori promoted Hiroyuki Yoshimoto to president last year, from executive vice president, while retaining the position of CEO for himself. Yoshimoto had come to Nidec from Nissan.
However, the motor maker's operation slumped amid the U.S.-China trade war, with consolidated net income declining 15% for the fiscal year ended in March. Yoshimoto this year traveled to the U.S., Mexico and Europe on a mission to bolster 15 overseas operations, including a large motor business, but failed to achieve satisfactory results.
Seki is highly regarded for his long manufacturing experience and deep knowledge of the U.S. and Chinese markets.
Nidec has carried out over 60 merger and acquisition deals, while hiring many executives from other companies in the automobile and electric appliance industries to help lead its rapid expansion. The company in 2014 appointed Mikio Katayama, a former Sharp vice president, to vice chairman.
Nidec recently hired many individuals from Nissan, Honda Motor and Mitsubishi Motors. Its haul from Nissan alone tops 200.