Callaghan had managed the European growth and European focus funds before being placed in a consultation period last month after the firm decided to restructure the European desk.
Head of the European desk Stephen Jones has taken on the funds in the interim, with mergers possible within the range.
Both Callaghan’s funds were in the bottom quartile of the Investment Management Association’s Europe (ex UK) sector over one and three years.
Callaghan joined Gartmore in May 2001 but looked set to leave to join Resolution Asset Management in June 2006 alongside Adrian Darley and Jon Fearon when a late move by Gartmore saw him stay.
Head of multi-manager Bambos Hambi left Gartmore recently when his desk was restructured, with Tony Lanning taking his place as head of the range of five funds, and investment trust chief Jim Tennant has also been replaced.
Hargreaves Lansdown investment manager Ben Yearsley says: “It is not surprising, given what has happened and the performance of the two funds Tim has managed recently.”