The president and chief executive of Nikko Asset Management, Takumi Shibata, is stepping down.
His resignation comes after he was named in a US lawsuit alleging he deliberately made lucrative stock options that were part of an incentive scheme for employees worthless.
The civil case was brought by 7 former employees of Tokyo-based Nikko Asset Management who are seeking a combined $100 million in damages. They say that Shibata and his co-defendants diverted funds earmarked for incentive schemes into new schemes that would benefit the defendants personally.
Nikko's statement announcing Shibata's resignation did not mention the lawsuit.
Shibata said: "I want to express my deep appreciation for the opportunity to lead this company for the last six years, surrounded by such global talent."
Under Shibata's leadership Nikko's assets increased from US$163 billion to US$202 billion and net income grew from US$49 million to US$77 million.
This is Shibata's second high profile resignation. He resigned from Nomura Holdings, where he was chief operating officer, in 2012.
Shibata will be replaced by Hideo Abe and Junichi Sayato, who will both be appointed as representative directors and co-chief executive officers. Abe will also hold the title of president and Sayato will be chairman.
Of his replacements, Shibata said: "Under Hideo Abe's leadership, sales, product and marketing have grown into highly effective efforts, while Junichi Sayato has strengthened internal controls under his operational leadership.
"With this in mind, I feel this is the right time to transition the company to those who have helped me shape it."
Shibata's resignation will be effective from April 1.