Cecil joins from Credit Suisse Private Bank where he has worked since 2007 as a private client advisor with the UK finance market professional team.
Prior to this he was a director at Kleinwort Benson for six years and head of UK equities and international portfolios.
His appointment follows that of Jonathan Colchester as head of private clients, UK and James Lindsay-Fynn as portfolio manager earlier this year.
GAM group head of private clients & portfolio management Graham Wainer says: “We are delighted that Rupert has joined our private client team in London and I am sure he will make an outstanding contribution. He has extensive experience of developing a strong and diverse client base, coupled with an outstanding knowledge of multi asset class solutions within an open architecture platform and creation of bespoke results for clients.”