Elms, who has been at Carat for five years, is leaving to pursue her outside interests. Greenstreet, who has been deputy managing director of Carat Insight since 2000, joined Aegis Media in 1993. He will oversee the 25-strong team responsible for driving research across Carat, Vizeum and Feather Brooksbank's clients.
Nigel Sharrocks, CEO of Aegis Media UK and Ireland, said: "Mark's influential thinking, management experience and client servicing skills make him ideally suited to take Carat Insight forward.
"Sue has played a big role in shaping Carat Insight into the market-leading force it now is. We're sad to see her go, but thank her for her contribution and wish her every success in the future."
Last week, Aegis Media named Martyn Rattle, chief operating officer at Vizeum, its global marketing director.
The appointment is part of the agency's wider restructuring programme, as part of which Mark Robison, Vizeum's worldwide head of marketing, left in March. Nine other senior positions have also changed across the network's international department.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .
.jpg)
.jpg)