Fidelity's flagship Magellan Fund, which recently lost its long-serving lead manager, generated 27% less in management fees in the six months to September 30 than in the same period a year ago, according to regulatory filings.

Management fee income for the period amounted to $104.3m (€88.5m) according to the fund's semi-annual report, filed with the Securities and Exchange Commission, the US regulator.