AuM reached £103.1bn by the end of March, up on the £101bn reported in the firm’s end of year results for 2016.
But the firm continued its lacklustre retail performance from 2016 with net retail outflows reaching £1.4bn in the first quarter of the year.
Investors reduced exposure to UK, European and Latin American funds in favour of absolute return strategies and emerging markets.
The asset manager’s quarterly trading results, published on Wednesday, also revealed it lost a further £0.4bn in its institutional arm.
However, a shift in the landscape saw sentiment brighten by the end of the quarter and outflows taper according to Henderson chief executive Andrew Formica.
He said the institutional losses were “one-off outflows” resulting from the restructure of its global equities team as it prepares to complete its merger with US fund manager Janus Capital.