Richard Buxton has resigned as chief executive of Merian Global Investors, but will continue as a fund manager, director and shareholder in the business.
Mr Buxton joined with five fund manager colleagues and private equity firm TA Associates to lead a buyout of the firm from parent company Old Mutual last year.
The business was renamed Merian.
Mr Buxton combined his role as manager of the £2bn Merian UK Alpha fund with the role of chief executive. But this morning (January 8) he announced that he regards it as the "right time" to resign as chief executive.
His replacement is Mark Gregory, a former chief financial officer at Legal & General, who became a director of Merian Global Investors in October.
Mr Buxton became chief executive in 2015, having joined the firm as a fund manager in 2013.
He said his long-term aim for the business was for it to become a boutique.
Commenting on his decision to stand down as chief executive, he said: "2018 was a momentous year for Merian Global Investors.
"With the management buyout and rebranding complete, I believe this is the appropriate time for me to hand over the CEO role.
"I am completely committed to the business and I will continue to be involved in its development, in my role on the board. Having known Mark for many years, I am absolutely convinced that he is the right person to take the business forward.
"My passion for investment is as strong as ever and I think there are some great opportunities in UK equities today.
"I will continue to seek undervalued and attractive businesses, while actively working with firms to improve corporate governance. I look forward to delivering long-term returns for our clients for many years to come."