Shelly Lazarus, chief executive of Ogilvy & Mather Worldwide and widely regarded as the most powerful woman in the advertising industry, will step down by the end of the year.

Ms Lazarus, 62, is to be replaced by Miles Young, who has overseen the WPP-owned advertising and marketing firm's fast-growing Asian operations for the last 13 years. She will remain as chairman of The Ogilvy Group. The move represents a rare management change at Ogilvy.