Universal had handled the US media buying for Coca-Cola for nearly two decades and the account becomes the latest slice of the brand's billings to slip from Interpublic's grasp.
Other losses include the bulk of the UK creative account, which switched from IPG's McCann-Erickson to Mother; the French creative, which moved from McCann-Erickson to Havas' BETC Euro RSCG, as well as other losses in Singapore and Vietnam.
Interpublic had already lost the US creative account from McCann. It moved in February into WPP Group's Berlin Cameron/Red Cell.
Shares in Interpublic fell by 0.7 per cent following news of the loss.
Starcom MediaVest, which already handles the media planning for Coca-Cola, won the account after a pitch against Universal McCann, WPP's MindShare and Carat.
As well as media for the core Coca-Cola brand, Starcom MediaVest will handle the media planning and buying for the Diet Coke, Vanilla Coke and Cherry Coke, Sprite, Powerade, Dasani, Fanta and Minute Maid juice brands.
Universal McCann remains the media agency of record in many of the 200 countries where the drink is sold.
McCann-Erickson still handles some UK creative agencies but earlier this year had trouble getting work approved by Coca-Cola. Work from WPP's Red Cell has subsequently aired, while Mother will create the brand's next major ad campaign.