Mercury Asset Management and Gartmore will be replaced by Morgan Grenfell and Baring Asset Management. Surrey's third manager, PDFM, retains its brief.
Surrey CC leader Nick Skellett, chairman of the fund's investment panel, said: 'This was a tough decision to make . . . but in the final analysis we have a duty to ensure our investment performance is top class.'
'In that way we can reduce the impact [of employer contributions] on the council tax payer and can concentrate our efforts and resources on services for the people of Surrey.'