Total FuM stood at 27.2 billion pounds at the end of December, the UK wealth manager said in a statement, up 3.4 percent from the September quarter and 23.6 percent from a year ago period.

Net flows for the quarter were at 327 million pounds. The acquisition of Jupiter Fund Management's private client and charity investment business also boosted the FuM in 2014.

Rathbones, which will issue results for 2014 next month, said results were anticipated to be in line with expectations.

"Although we expect investment markets to continue to be volatile in 2015, our outlook remains positive," the wealth manager said in the statement.

At 0823 GMT, Rathbones' shares were trading up 0.9 percent, outperforming a 0.4 percent rise in the FTSE Mid-cap index <.FTMC>.

(Additional reporting Nishant Kumar; Editing by Matt Scuffham)

By Carolyn Cohn