In his new role Plant will have responsibility for leading the planning within MEC's real time bidding operation, using insight from social media, search and customer data to inform campaigns on a live basis.
Plant will also have responsibility for strategic planning on the Lloyds Banking Group business. He will report to Stuart Bowden, MEC’s managing director, and head of strategy Verra Budimlija..
At Vizeum UK as head of integrated communications planning from October 2011 and strategy director from September 2008, Plant worked with clients such as Ikea, BMW and InBev.
Prior to joining Vizeum Plant was an account director at Mindshare between April 2006 and August 2008. Between 2000 and 2006 he worked at ZenithOptimedia, Rocket and Manning Gottlieb OMD.
Stuart Sullivan-Martin, chief strategy officer at MEC, said: "Increasingly our work for our clients involves being fast, dynamic and nimble with the wealth of data we have at our fingertips.
"This means not only 'hard' customer data but also the patterns we find in search, and the qualitative insight we can gather from conversations in social media.
"[Plant will] be leading the charge to make this an even bigger part of our business, as well as working with some of the biggest brands in the agency."