3i will be the first FTSE 100 company to be chaired by a woman when Baroness Sarah Hogg replaces Sir George Russell on his retirement at the end of the year.
Hogg joined 3i in 1997 as a director and became non-executive deputy chairman a year ago. Brian Larcombe, 3i's chief executive, said: "Sarah has been on the board as a non-executive for about four years. She has been fully supportive of the directors in their execution of 3i's strategy. She is a strong believer in the strategy."