Caspar Rock, who has been with AXA for 21 years and with Architas for eight years, is moving to Cazenove Capital Management, where he will have the same job title.
Mr Rock will retain his current responsibilities until his departure in Q3 this year and will "help to oversee an orderly transition".
He said: “Whilst this is a change in direction for me personally, I am looking forward to the new challenge that this role will create. This is a great opportunity to join a market leader in wealth management with a brand name that is one of the strongest in the industry.
“I am very proud of the strong investment team that we have built at Architas and our investment performance. I leave the funds in very capable hands.”
Andrew Ross CEO of Cazenove Capital Management said: “We are delighted to have attracted such an experienced investor with a demonstrable track record as our CIO and I look forward to working with Caspar to realise the full potential of our wealth management business.”
Hans Georgeson, Architas chief executive, said potential replacements are being lined up.
He said: “We have exceptional internal and external candidates for the role and expect to confirm a new CIO shortly. We have an excellent business, and this is a great role, so interest has been very strong."
He said: “Over the past five years Architas has become one of the fastest growing multi-managers in Europe. Caspar has been instrumental to this but has decided on a career change and is leaving the multi-manager world to move into capital management. We wish him well in his new role and would like to thank him for his dedicated service with Architas and the wider AXA Group.
“In Sheldon MacDonald, Steve Allen, Nathan Sweeney, Anna O’Donoghue, Remi Lambert, Daniel Capocci and Seamus Lyons, Architas has highly experienced, talented investment managers and teams, with market-leading capabilities and the resources of a global company.
“Our top priority is to look after our clients’ interests through a well-ordered transition process.”