Its shares jumped more than 5 percent to their highest since early January.

A slide in the value of sterling in the weeks after the end-June vote had helped boost British shares and the value of the firm's assets, and it said on Tuesday it had yet to see any weakening in investor sentiment despite the uncertain economic and political outlook.

Persistently low interest rates underpinned demand for its pension and investment products, as clients put greater store in the firm's face-to-face advice.

"People are looking for income, they're looking for alternatives to that (low interest rates)," Chief Executive David Bellamy told Reuters.

The company, which offers a range of services including investment funds, pensions and tax planning, said funds under management at end-September grew to 71.4 billion pounds ($87.3 billion) from 65.6 billion at the end of June.

Gross inflows were 2.8 billion pounds, led by strong demand for its pension products as more clients took advantage of rules designed to give them more control over how their retirement savings are invested.

Net inflows were 1.7 billion pounds, while positive market movements added a further 4.2 billion pounds to total assets, it said in a statement.

"Despite the backdrop of political uncertainty, it's been very much business as usual and we've maintained good momentum in the business since the half year," Bellamy said in a statement.

Shares in the firm were up 2.5 percent at 972.5 pence by 0740 GMT, among the top gainers in the FTSE 100 <.FTSE>, after initially rising to 1,003p, their highest since Jan. 1.

"Despite considerable political upheaval and market volatility, St James's Place has issued an excellent Q3, reporting inflows and funds under management which comfortably exceeded both our and the market's expectations" Shore Capital analyst Eamonn Flanagan said in a note to clients, flagging a "buy" rating on the stock.

(Editing by Sinead Cruise and David Holmes)

By Simon Jessop