The agency took the business following a competitive pitch against Carat, OMD and the Starcom Group, which kicked off last October.
MEC will handle Remy Cointreau's full portfolio of global brands, which include Remy-Martin, Bols, Piper-Heidsieck, Bokma and Metaxa. It will run the business from its Paris office, led by the managing partner Blandine Pillot.
The only brands to have advertised in the UK are Cointreau and Remy Martin, according to Nielsen Media Research. Starcom and AMS Media looked after these two accounts respectively.
The move cements an existing relationship between Remy Cointreau and MEC - the agency has held Remy-Amerique for the past seven years. The win also strengthens MEC's association with Maxxium, which distributes Jim Beam, another drink brand handled by the agency.
"As a premium brand company, we spend a large percentage of our margin on communications every year," John Glover, the strategic marketing director at Remy Cointreau, said.
"By working with MEC we hope to maximise the effectiveness of our spending to make our communication planning and placement more cost effective.
"MEC has a compelling track record in leading assignments of this nature and we fully expect it will help us realise this opportunity."