Mr Manduca, 42, will take over as chief executive of BAT's Threadneedle Asset Management, which looks after pounds 30bn, in six weeks' time. Henderson had planned to confirm Mr Manduca as the successor to Jeremy Edwards in its next report and accounts in June.
Henderson and Mr Manduca rejected any suggestion that they had fallen out. Mr Manduca said Threadneedle offered a new opportunity and a big job. It is thought he will receive a salary to match.
He said: 'It brings a group together which will have good distribution, a large direct sales force and critical mass across certain of its businesses.' Threadneedle was formed by merging the investment arms of Allied Dunbar and Eagle Star, BAT's UK insurers.
Mr Manduca joined Henderson as deputy managing director nearly 18 months ago when it bought Touche Remnant, the investment trust manager which he headed, from Societe Generale of France. The pounds 42.5m deal created Britain's largest investment trust manager.
It was hoped that the Touche Remnant team would help to bring an end to Henderson's long-running loss of pension-fund clients that stemmed from bad investment performance in 1987 and 1988. Mr Manduca was an obvious candidate to replace Mr Edwards, due to retire at 60 in early 1997.
Threadneedle plans to seek business from external clients. Mr Manduca said distribution capability would become increasingly important for investment managers.
Full disclosure of commissions in the life insurance industry would make customers look closely at investment performance.
Threadneedle was to have been headed by Allied Dunbar's Kenneth Inglis but he left to become chairman of Fleming Investment Management.Reuse content