Michaelsen replaces Risto Maila, who was group managing director for the German-speaking countries and Benelux. Maila is leaving Nielsen at the end of this month after ten years as a result of the reorganisation.

Michaelsen (pictured) has been with Nielsen for a similar amount of time, most recently with responsibility for Scandinavia, the UK and Ireland. He will retain responsibility for Scandinavia alongside his new role.

Sargent began his career as a category marketing analyst with Procter & Gamble before joining Nielsen in 1993. He was promoted to UK MD in January 2008. Prior to that he was UK executive commercial director.