Barnes is to be replaced by chairman Ray Greenshields, who thanked him for his contribution to the business.
Barnes’ departure will come as surprise to many given that in an interview with Money Marketing earlier this year he said that he would be with the firm in the long run.
He has been at the centre of much controversy following the purchase of the firm by 3i in 2007, following the departure of numerous members of staff, including head of communications Justin Modray.
At the time of his departure Modray said: “The arrival of a new CEO has seen a fair amount of change at Bestinvest this year, causing me to become increasingly unhappy over certain issues. As a result, I have reluctantly parted ways with the company.”
A spokesperson on behalf of Bestinvest said the group was unavailable for comment.