The company has hired Steve Rafferty in the new role, which was effective from 4 November.
Mr Rafferty was formerly at BlackRock for 16 years, most recently as global COO for the fixed income division, where he was responsible for the operating integrity of the $2trn fixed income business.
GAM says the qualified accountant and CFA brings two decades of experience in asset management.
He reports to Peter Sanderson, group chief executive officer, and is responsible for overseeing GAM’s day-to-day global business and ensuring that the business has the connectivity, coordination and operating processes required to meet its strategic goals.
Mr Sanderson said: “Reducing complexity, as well as strengthening our core business and improving profitability, are fundamental to the future of GAM.
“Steve has a demonstrable track record in designing and implementing improvements across a global business and his appointment will further support us in achieving our objectives.”