Veteran manager Gervais Williams has resigned from Gartmore and will leave the firm at the end of September.
Williams was head of UK smaller companies and ran the £54m Growth Opportunities, £84m Fledging and £47m Irish trusts as well as the £150m UK & Irish Smaller Companies Oeic.
He has been replaced by Adam McConkey, who joined Gartmore in 2000 and is a senior investment manager in the UK Smaller Companies team. He will report to CIO Dominic Rossi.
Williams' resignation comes just weeks after Gartmore said it had suffered £2bn of net outflows so far in 2010, largely as a result of the suspension and subsequent resignation of star manager Guillaume Rambourg.
Rambourg was suspended from work in the spring before handing in his notice in July to defend an official FSA probe into his share dealings.
McConkey has over 11 years' investment industry experience and also holds a PhD in International Relations from Loughborough University.
Gartmore says Williams has left the company to pursue other interests.
Rossi says: "It is testament to the strength in depth in the Gartmore UK Smaller Companies team we can call upon a manager of Adam's calibre.
"We are confident that, with the support of the hugely experienced Rob Giles and the rest of the team, Gartmore will continue to be a leading light in the specialist management of UK small-cap equities. We would like to thank Gervais for his contribution to Gartmore over many years."
McConkey and Rob Giles, senior investment manager, will co-manage the Gartmore UK & Irish Smaller Companies Oeic which has returned a decline of 2.5% over five years to 23 August 2010, compared to an IMA UK Smaller Companies sector average of 16.1%.
They will also continue to manage the AlphaGen Volantis hedge fund and Dublin domiciled Gartmore UK Small Cap Best Ideas fund.
New manager details for the investment trusts will be announced by the respective boards in due course.
Annuity market worth £4bn in 2017
For ‘distress’ caused
Oversees £30bn of advised and D2C assets
Less than a third of top paid employees are women
£1bn business since inception