The six-strong team, led by head Mr Plackett, runs £4.8bn of assets including the £1.9bn UK Special Situations fund and the £900m UK Emerging Companies hedge fund.
UK Special Situations has produced a top-quartile return of 55.1 per cent in five years to May 23 compared with the IMA UK All Companies sector average of 34.6 per cent, according to FE Analytics.
The group said Mr Whitestone would work as a director within the top-performing team from June 1 and be involved on all of the team’s funds although would initially focus on UK Emerging Companies.