Craig Baker, who runs the equity portfolio of the £2.9bn Alliance Trust, has revealed how he will shake-up the make-up of the investment vehicle.
The management of Alliance Trust's equity portfolio has been outsourced to Willis Towers Watson, where Mr Baker is chief investment officer.
He will select a pool of firms to manage the capital on a multi-manager basis.
Mr Baker said each fund manager has worked with Willis Towers Watson for a long time and, in many cases, have agreed to run money for Alliance Trust in a way not currently made available to advisers.
He said: "The managers chosen know we are willing to be long-term. They know we will not remove them for a year or two of bad performance, as long as we know what is the reason behind the performance.
"If anything, if a manager has had a run of very strong performance we are likely to take a bit of money off them and give it to a manager that has had a bad run of performance.
"This is because the manager having a good run may be doing so because the style of investing they use is in fashion, while the style of investing used by the manager underperforming may be out of fashion.
"But if that is happening, the appropriate reaction may be to switch because the styles will go in and out of favour."
He said he would only withdraw cash from a particular manager if he felt the style that the manager had used throughout his career was being abandoned.
The eight fund managers are Jupiter's Ben Whitmore, who uses a "value" style of investing, River and Mercantile’s Hugh Sargent, also a value investor, GQG's Rajiv Jain, who runs global and an emerging market growth mandate, Andy Headley at Veritas Asset Management, Andrew Wellington of Lyrical Asset Management, George Fraise at Sustainable Growth Investors, Pierre Py at First Pacific Advisers and Bill Kanko at Black Creek Investment Management.
Alliance Trust has been dramatically overhauled by the board of directors, with the open-ended fund business sold to Liontrust.
But Alliance Trust continues to own the Alliance Trust Savings platform and some other investments.
Mr Baker said the question he gets asked most often is about the future of the Alliance Trust platform.
He said that while the trust's board has committed to selling the other non-core assets, the future of the platform remains unresolved.
Paul Milburn, who works for IFA firm Lowes Financial Management in Newcastle, said: "We certainly wouldn’t change a manager or fund we recommend simply based on performance. We understand styles can come in and out of fashion.
"Our aim is to have balanced portfolios, so if you sell a manager because the style they use is out of favour, you end up with portfolios entirely focused on one style and then when that style falls from favour the whole of the portfolio suffers."