The gain was set against a fall of 0.7 per cent over this period in the FTSE 100 Index of blue-chip stocks and a rise of 0.6 per cent in the FTSE WMA Balanced Index over that period, the firm said in a statement.

Total net organic and acquired growth in the funds managed by Rathbone Investment Management was £600 million in the first six months of 2015, representing a net annual growth rate of 5.1 per cent (2014: 12.2 per cent). Net organic growth of £300 million for the first half represents an underlying annualised rate of net organic growth of 2.8 per cent (2014: 4.1 per cent).

The firm said its underlying pre-tax profit rose by 27 per cent from £29.3 million to £37.2 million in the six months to end-June from a year earlier, representing a margin of 31.9 per cent.

Basic earnings per share increased 3.9 per cent to 53.2p.