GAM has hired former Artemis star fund manager Adrian Gosden.
The business did not immediately specify what role Gosden will join in, although it is likely given his experience he will be running UK equity income assets.
GAM declined to comment on the appointment.
In his last five years at Artemis, Gosden returned 50.12% within the UK Equity Income sector while the average sector peer manager returned 51.14%.
Prior to Artemis, Gosden managed a number of accounts for institutional clients and co-managed the retail SocGen UK Income fund with Nicola Horlick.
GAM is looking for growth on multiple fronts. Earlier this summer the company expanded its private clients and charities business with the hire of UBS portfolio director Perhad Merwanji.
Also in July, Columbia Threadneedle Investments' Adam Brown started as the business' global head of marketing.
In June, the company revealed that client assets within GAM's five-strong range of model portfolios, launched in late 2012 and managed by Charles Hepworth and James McDaid, had climbed above £1 billion.