The decision follows a comprehensive agency assessment conducted jointly by Mars and Wrigley China to consolidate planning and buying responsibilities for all media within these business segments.
The formal review, which included MEC, Zenith Optimedia, OMD and Starcom, follows the global merger of Mars and Wrigley, which took effect on 6 October 2008. OMD was believed to have been excluded from the final round of the pitch.
Jean Zhang, vice president of marketing for Mars China, commented: "We have selected Starcom due to their demonstrated thought leadership and go-to-market approach. Zenith is a world class agency which has made a great contribution towards the growth of Mars China last year and we value their capabilities and talent, as well their drive for excellence."
Clarence Mak, director of marketing for Wrigley China, added: "The selection of Starcom was driven by the clear and joint business needs that ensure Mars and Wrigley have the long-term structure in place to deliver strong performance while strengthening our competitive advantage and bringing additional value to our consumers."
Mak added that "MEC is a world-class agency with talented, dedicated people and we wish them the best in the future, and appreciate the many contributions, hard work and professionalism they have demonstrated throughout our relationship."
GroupM's MEC has handled Wrigley China's media buying and planning since 2005, while Zenith Optimedia has handled Mars China's media planning and buying since 2009. Both of their contracts will end on 15 July.
Mars Inc is one of the world's largest food companies, generating global revenue of more than $30 billion annually and operating in six business segments including chocolate, petcare, Wrigley chewing gum, food, drinks and symbioscience.
Leading brands within these segments include Mars, M&M'S, Snickers, Dove, Pedigree, Whiskas, Orbit, Extra, Doublemint and Skittles, among others.