Mercer's Paul O'Connor is to join Henderson as a director on its multi-asset team. He will be involved in the management of an institutional strategy called Diversified Growth when he assumes his role at the firm on 28 January.
Henderson's European equity managers Bill Stormont and Paul Casson have both left the firm, along with smaller companies manager Simon Savill.
Henderson non-executive chairman Rupert Pennant-Rea is to stand down in May 2013 to take a similar role at Royal London Group.
Tatton Investment Management (TIM) has teamed up with Distribution Technology (DT) to launch online tools for advisers and their clients.
Henderson Global Investors is set to announce a fresh round of job cuts before the end of the year, Investment Week understands, as the FTSE 250-listed asset manager embarks on a further cost-cutting drive.
A high court judge has ruled against the 22 pension funds attempting to sue Henderson Equity Partners for allegedly breaching the mandate for its Private Finance Initiative Secondary Fund II.
Henderson reported net outflows of £1.1bn in Q3, with net retail outflows making up £296m of the total.
James Hay has added more than 100 new funds to its platform, including a number of risk-rated and multi-manager offerings.