Rathbones's assets under management (AUM) fell by 3.3 per cent in the first quarter of 2018 as turbulence in equity and bond markets took its toll.
Total assets at the end of March 2018 were £37.8bn, with net inflows of £199m, compared with £318m in the same three months of 2017.
The unit trust business had net inflows of £143m but investment performance was negative, meaning the total assets were flat, at £5.3bn, the same figure as for the final three months of 2017.
Despite the drop in assets under management for this part of the business, the income earned by Rathbones rose by 20.5 per cent, to £8.8m, compared to £7.3m for the same quarter last year.
This mirrored an increase in income for the whole business, which was £66.6m, compared with £63m for the same quarter in 2017.
Philip Howell, chief executive of Rathbones, said: "Although investment markets fell back a little in the first quarter of 2018, trading was solid with net operating income up 6.8 per cent from the same period last year.
"Total funds under management fell 3.3 per cent during the quarter, compared with decreases in the FTSE 100 Index and the MSCI WMA Private Investor Balanced Index of 6.4 per cent and 3.8 per cent respectively."