Omnicom acquires Interpublic Group ($13.25B)

On December 9, 2024, Omnicom and Interpublic announced a definitive agreement for Omnicom to acquire Interpublic in an all-stock transaction (equity value ~$13.25 billion; enterprise value ~$16.7 billion incl. debt). Interpublic shareholders received 0.344 Omnicom shares per IPG share, leaving legacy Omnicom holders with ~60.6% and legacy IPG holders ~39.4% of the combined company. The combined entity retains the Omnicom name and the OMC ticker on the NYSE. Both companies’ shareholders approved the merger on March 18, 2025. The U.S. FTC closed its antitrust review with a consent order on June 23, 2025; the European Commission granted unconditional clearance on November 24, 2025 (the final required regulatory approval). The transaction CLOSED on November 26, 2025. The deal reshapes the agency landscape, vaulting the combined Omnicom past WPP and Publicis to become the largest advertising holding company by revenue, with particular scale in data (Acxiom/Flywheel + IPG’s Kinesso/Acxiom heritage), media buying, and retail media. Brand consolidation followed (e.g., DDB retired as a standalone brand on December 1, 2025).