Rock’s departure to join Cazenove Capital Management was announced in April.
Subject to regulatory approval Arguello joins Architas from Barclays where he has been managing director and CIO for its £17.5bn multi-manager and alternatives business for the past seven years. His start date at Architas is yet to be finalised.
Prior to this he spent 10 years at Pictet as director of third party manager selection and head of fixed income. He has over 30 years industry experience covering the full range of asset allocation, fund selection and portfolio management.
Arguello and the team will be responsible for over £20bn in assets under management and advice across the Architas group of businesses in the UK and Europe.
Architas CEO Hans Georgeson said: “I am pleased to confirm the appointment of Jaime given his experience and clear investment integrity. He has been responsible for managing significant assets on an open architecture basis, for managing large investment teams, and brings to the role both technical knowledge and global investment experience."
“Based out of London, Jaime’s fit with the business is very strong and his experience in managing alternatives, multi-asset and single asset class funds complements the nature of our business extremely well,” Georgeson continued. “Jaime joins us at an exciting time as we focus on investing in our UK business, including the imminent launch our first range of managed portfolios. Jaime and the investment team will be integral to driving this growth and working with advisers in the UK to support the needs of their clients.”