The chief investment officer of Newton Investment Management has decided to leave, prompting chief executive Helena Morrissey to become more involved with day-to-day oversight of the investment team.

Simon Pryke, who had been in charge of investment strategies at Newton, will leave the firm after almost 20 years. Charles French, head of Newton's financials and consumer research team, will become head of investments, according to an internal memo seen by Financial News. French has worked at Newton for 15 years.