Legal and General chief executive Tim Breedon is retiring from the firm at the end of next year.
Breedon joined L&G in 1987 and became group chief executive in January 2006.
L&G says it will start the process of identifying and appointing his successor over the next few weeks.
Breedon says: “It has been an absolute privilege to lead L&G but by the end of 2012, I will have completed 25 years’ service with the company and will have been chief executive for seven years.
“With the company in excellent shape, I feel that next year will be the right time to retire from the company.
“By giving notice of this now, the board will have ample time to plan and ensure an orderly succession.”
Last month, L&G announced that it is raising its interim dividend by 25 per cent despite profits falling by 12 per cent in the first half of 2011 to £473m, down from £537m in the first half of last year.
Breedon said a 19 per cent increase in operational cash generation from £417m to £498m has allowed the firm to boost its dividend from 1.33p per share to 1.66p.