Omnicom Group Inc.

Merger with IPG On November 26, 2025 (the Closing Date ), Omnicom completed its Merger with IPG (the Merger ). As previously reported, on December 8, 2024, Omnicom entered into an Agreement and Plan of Merger (the Merger Agreement ) with IPG and EXT Subsidiary Inc., a Delaware corporation and a direct wholly owned subsidiary of Omnicom ( Merger Sub ). On the Closing Date, pursuant to the terms and conditions of the Merger Agreement, Merger Sub merged with and into IPG, with IPG continuing as the surviving corporation and a direct wholly owned subsidiary of Omnicom. Upon the Merger, each outstanding share of IPG common stock (other than certain excluded shares) converted into the right to receive 0.344 shares of Omnicom common stock and cash in lieu of fractional shares. Following the closing of the Merger, legacy Omnicom shareholders owned approximately 60.6% of the combined company and legacy IPG shareholders owned approximately 39.4%, on a fully diluted basis (see Note 5 to the consolidated financial statements). Omnicom’s common stock continues to trade on the New York Stock Exchange, or NYSE, under the symbol OMC, and IPG’s common stock has ceased trading. The Merger qualified as a tax-free reorganization for U.S. federal income tax purposes, and the combined company operates under the Omnicom name with headquarters in New York, New York. Omnicom is the acquirer of IPG under U.S. generally accepted accounting principles (U.S.