Chief executive Paul Feeney blamed negative market movements for overall AUMA falling 2.4% to £111.6bn ($153bn €127bn) compared to £114.4bn in Q1 2017.
Excluding the impact of net inflows, market fall alone accounted hit AUMA by 3.8%, although Feeney noted the FTSE 100 fell 8.2% over the period.
Net inflows over the period were £1.6bn compared to £1.4bn in Q1 2017.
Looking ahead, Feeney said: “While there has been some recovery in market levels so far in the second quarter, we anticipate continued uncertainties in equity, bond and currency markets in the medium term as any potential impacts of the UK’s exit from the EU evolve and given geopolitical and economic risks.”
Feeney welcomed the formal process of Quilter’s listing on the London and Johannesburg stock exchanges.
Old Mutual shareholder approval will be sought for the managed separation at a general meeting on 25 May 2018. The UK court will also conduct two separate meetings preceding the shareholder vote.