He will take up the role next year, when his lock-in period at JM Finn expires.
Edgedale announced at the end of July that he was leaving JM Finn, where he had spent his entire 37-year career.
He stepped down as chairman of the £11bn Aum firm in September 2020, but remained as a non-executive director, and managed some capital for clients.
FTAdviser has now learnt he is to join Vermeer, an investment management firm formed by a group of veteran investment managers, some of whom previously worked together at Cheviot, which is less than two years old and has £1.8bn of assets under management.
In his role as joint chairman, Edgedale will work with Michael Kerr-Dineen, the existing Vermeer chairman, who is a former chief executive of UBS Wealth Management and a founder of Cheviot, which he subsequently merged with Quilter, before departing.
Edgedale will be assisted in his role by William Buckhurst, the firm's head of fund research, who will retain his current responsibilities while helping the new joint chairman with tasks such as onboarding new staff.
Of the appointment, Kerr Dineen said: “Bringing James on board is an important milestone for Vermeer Partners. He is a highly talented operator, with a very strong reputation in the industry both as a business leader and an investment manager.
"We are delighted James has chosen to join our partnership to work alongside colleagues who are longstanding and experienced investment managers.
"James understands our ethos, and I know he will fit into the culture of the firm.”
At JM Finn, Edgedale was senior partner when the firm ceased to be a partnership and became a private company, of which he was subsequently appointed chairman. He served as chairman from 2011 to 2020.
Vermeer is owned by around 30 partners, with a total workforce of just over 40.
The chief executive of Vermeer is Simon Melling, whose previous roles include chief executive at stockbroker Cenkos Securities.