Shares of Nissan fell 2.6 per cent in Tokyo on Wednesday after several news outlets reported that a top executive would abruptly leave the Japanese automaker.

Vice chief operating officer Jun Seki told Reuters, Bloomberg and Japanese media that he plans to join the Japanese manufacturer Nidec Corp. as president and COO. Nissan told CNN Business that it was aware of the reports but declined to comment. Nidec also declined to comment.

It's been a rough year for Nissan. The company has struggled to recover from the ousting of former chairman Carlos Ghosn last year, which strained Nissan's alliance with Renault and Mitsubishi.

Nissan has also posted a string of lackluster earnings quarters and in July announced plans to cut 12,500 jobs worldwide. Last month, the company also cut its sales forecast for the year and said it expects to sell less cars than expected for the fiscal year that ends in March 2020.

Reports of Seki's departure also come more than two months after Nissan selected a new chief executive officer. Makoto Uchida took the role after Hiroto Saikawa resigned. Saikawa admitted that he and other Nissan executives were overpaid as part of a stock-related payment plan, though he denied any wrongdoing.

Bloomberg described Seki as one of the contenders to replace Saikawa before Uchida was tapped.

The Japanese news source Diamond Online quoted Seki as saying that he was not quitting because of troubles with the alliance.

"I would not say there is no confusion in the management," he told Diamond. "But it's not the reason I leave."

Seki told Reuters that Nidec, which produces specialist car parts, was an offer he could not refuse.

"I love Nissan and I feel bad about leaving the turnaround work unfinished," he told Reuters. "But I am 58 years old, and this is an offer I could not refuse. It's probably my last chance to lead a company, too."

Japan's Nikkei 225, of which Nissan is a component, was down 0.1 per cent Wednesday morning. China's Shanghai Composite was flat.

Other major indexes, including Hong Kong's Hang Seng and South Korea's Kospi, were closed for the Christmas holiday.