Prior to Starcom MediaVest, he was deputy managing director at search independent Net Media Planet, and, before that, was head of search EMEA at MEC: Interaction, where he was responsible for leading the Monster.com account across 16 markets.
Carstens said: "SMG understand the value and the role that search plays for the agency, their clients, and the wider communications landscape. They’ve invested in building an outstanding team and have made incredible progress in the last 18 months."
Nigel Waring, head of SMG Performance, said: "[Rian will] be integral in leading locally and taking UK best practice wider across the network"
SMG’s search team currently manages paid-search campaigns for clients such as Honda, Bupa and Europcar.
According to Starcom MediaVest, its search team has doubled in size and trebled its revenue in the past 12 months.