SVG Advisers, the UK private equity manager whose parent has been paring back allocations after its "most difficult" year, has suffered a ratings downgrade on its structured products fund that could further restrict the amount of money it has to invest.

Ratings Agency Fitch is adjusting the credit ratings on about $350m (€258m) of different tranches of SVG Diamond Private Equity II, financed in part by the group's listed affiliate SVG Capital. The fund uses leverage to invest in private equity funds and also second-hand stakes in them. It raised €500m ($666m) in 2006.