AssetCo has announced that Campbell Fleming has decided to step down as chief executive.
He oversaw the formation of the company, completing a series of acquisitions and guiding their integration.
Fleming is leaving for personal reasons and his last day will be 30 June.
AssetCo will not be replacing him directly, with Martin Gilbert and Gary Marshall instead assuming his principal responsibilities, with Gilbert as executive chair being responsible for the overall strategic direction of the group and Marshall overseeing day-to-day operations as chief financial and operating officer.
Alex Hoctor-Duncan, chief executive of AssetCo's principal operating company, River and Mercantile, is already taking on additional responsibilities as the group's active equities businesses integrate under that brand.
Gilbert commented: "On behalf of the board, I would like to thank Campbell for his contribution to the development of AssetCo.
"We grateful to Campbell for his efforts and hope to continue our long association with him in supporting and guiding some of our underlying businesses."
Fleming said: "It was the right business and personal decision to step down after an extremely demanding 20 months integrating the group and as I now look to pursue additional non-executive roles.
"I will continue to support, as well as remain a shareholder of, AssetCo as I believe in its strategy, team and its people who continue to deliver for our clients as shown by our results."
Separately, M&G Wealth managing director David Montgomery is set to leave at the start of August.
The Scotland-based leader was lured back from US-based insurance firm Transamerica in September 2020 to lead the platform’s £28bn wealth management division.
His departure follows the announcement that head of retail and savings Clare Bousfield will be leaving.
The firm is replacing her with two chief executives for its wealth and life insurance businesses.
A spokesperson for M&G Wealth stated: "We can confirm that David Montgomery has decided to stand down from his role as managing director of M&G Wealth at the beginning of August.
"We would like to thank him for everything he has achieved in his time at M&G and wish him all the very best for the future."
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