Charnock, chief executive of Standard Life Wealth, will take up his position on the board on January 1.
Keith Skeoch, Standard Life Investments’ chief, said there were "substantial opportunities" to grow the business, so the merger made sense as it would allow the discretionary arm of the business to capitalise on the wider group’s infrastructure.
He said: “Following the acquisition of Newton Private Clients, Standard Life Wealth has become a substantial asset management business, which has created a deeper operational and investment link between our two companies. It now makes sense to align our two businesses more closely.
“We believe this is a very positive move for both companies and will give Standard Life Wealth greater access to our global investment platform, investment performance and investment solutions. Over the next few months we will be working together closely to make sure the move goes smoothly for our businesses, our people and our clients.”