The company said its funds under management were £19.6bn as at the end of March 31, up 8.9 per cent from £18bn as at December 31 2012.
But the group noted that throughout April inflows had continued and that the firm now ran £20.1bn, including £339m from the acquisition of Taylor Young’s private client business.
The group’s chairman Mark Nicholls also said the company saw its net operating income increase by 10 per cent year-on-year.
The group’s funds business, Rathbone Unit Trust Management, saw funds under management increase 10.8 per cent to £1.4bn as at March 31 compared with £1.3bn as at December 31 2012 with net inflows of £23m during the quarter.
“Our outlook is positive and we continue to invest in people and systems while managing costs carefully,” Mr Nicholls said.
“Rathbones now manages more than £20bn of funds and is well positioned to take advantage of healthier investment markets and future growth opportunities.”
The statement said commission income was “strong”, reflecting market movements and normal seasonal patterns in the run up to the end of the 2012/13 tax year.
Net interest income of £2.1million in the first three months of 2013 was 19.2 per cent lower than the £2.6m earned in the corresponding period in 2012 “largely as a result of lower yields on treasury assets” which the company said are expected to continue.
Cash in client portfolios averaged £910m in the first quarter of 2013 compared with the 2012 average of £944m.