The consolidation will see Coca Cola drop Bcom3's Leo Burnett and D'Arcy. Another casualty will be Portland based Wieden + Kennedy.
Leo Burnett handles the $40m (£27m) Minute Maid account, while D'Arcy has its Coke Classic's NASCAR advertising. Wieden handles Diet Coke and Powerade which are estimated at $25m (£17m) and $60m (£41m) respectively, according to US reports.
Interpublic agencies are thought likely to pick up Diet Coke, Powerade and Minute Maid. Interpublic agency Lowe & Partners already handles Coke brand Sprite, which will be moved to O&M with billings of $85m (£58m).
It has also been reported that O&M will pick up Coke's Fanta brand, which was previously split among a number of agencies including Cliff Freeman & Partners, which resigned the account recently.
Earlier this year Interpublic agency McCann-Erickson was appointed to the task of rejuvenating Coca-Cola's flagship brand through a major global advertising blitz. The decision followed the appointment of Interpublic as Coca-Cola's global communications consultant last December.
It was not known at the time how the appointment would affect Coca-Cola's relationship with Publicis, which, following this latest realignment, must be in doubt. Publicis beat McCann-Erickson and Leo Burnett to win Coke's European account last November.
Publicis' appointment was the first by Coca-Cola on a regional basis. However, the agency's position appeared to be quickly weakened by the Interpublic appointment a month later.
Coca-Cola spends an estimated £1bn (£680m) advertising its flagship brand worldwide.
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