George Sauter, the managing director and chief investment officer of Vanguard, has announced that he will retire at the end of the year. Sauter has been with the firm since 1987 and currently directs the firm's investment management groups. He will be succeeded by Mortimer Buckley, a managing director who has been director of the retail investors group since 2006. He has been a member of the senior staff since 2001, and is a member of the portfolio review group.