Brooks Macdonald has seen its funds under management increase by 3 per cent to £12.8bn over the three months to the end of September.
This was driven by net new business, which added £158m, and investment performance, which added £211m, as the company rode out the recent market volatility.
Over the course of 2018, Brooks Macdonald's assets were up 16.4 per cent.
Caroline Connellan, Brooks Macdonald's chief executive, said: "We have maintained positive momentum in our UK business over the first quarter, with good organic growth despite softer client sentiment in light of the current macroeconomic environment.
"The ongoing strength of our investment performance has been particularly pleasing, driven by our centralised investment process and the expertise within our teams.
"High quality active investment management is of particular importance in what continue to be difficult market conditions and we remain focused on continuing to meet our clients' and advisers' expectations."
Over the course of the year Brooks Macdonald also opened its East Anglia office in Bury St Edmunds and launched a responsible investment service.