Stockholders Approve Omnicom’s Proposed Acquisition of Interpublic

Approval marks key milestone in the process to combine the two companies

NEW YORK, March 18, 2025 – Omnicom (NYSE: OMC) and Interpublic (NYSE: IPG) today announced that each company’s respective stockholders overwhelmingly approved Omnicom’s previously announced acquisition of Interpublic at each company’s Special Meeting of Stockholders held today. The companies remain on track to complete the transaction in the second half of 2025.

Stockholder approval marks an important milestone in the process to combine Omnicom and Interpublic, which will bring together the industry’s deepest bench of marketing talent, offering the most innovative services and products, all underpinned by an advanced sales and marketing platform.

“We are very pleased to reach this important milestone. The strong support of our stockholders confirms the compelling value proposition of the transaction and the leading-edge services, products and platforms it will create for our people and clients,” said John Wren, Chairman and CEO, Omnicom.

“With an overwhelming majority voting in favor of the transaction, it is clear that our stockholders see the immense opportunity of Interpublic joining forces with Omnicom,” said Philippe Krakowsky, CEO, Interpublic. “Their approval reflects the tremendous potential we have to create one of the most dynamic, client-focused, and forward-leaning organizations in our industry that will deliver significant shareholder value for years to come.”

The companies expect the transaction will close in the second half of 2025, subject to required regulatory approvals and other customary conditions. As previously announced, upon completion of the stock-for-stock transaction, Interpublic shareholders will receive 0.344 Omnicom shares for each share of Interpublic common stock they own. Following the closing of the transaction, Omnicom shareholders will own 60.6% of the combined company and Interpublic shareholders will own 39.4%, on a fully diluted basis.

The final voting results for each company’s Special Meeting will be filed with the U.S. Securities and Exchange Commission in separate Current Reports on Form 8-K and will be available at investor.omnicomgroup.com and investors.interpublic.com.

About Omnicom

Omnicom (NYSE: OMC) is a leading provider of data-inspired, creative marketing and sales solutions. Omnicom’s iconic agency brands are home to the industry’s most innovative communications specialists who are focused on driving intelligent business outcomes for their clients. The company offers a wide range of services in advertising, strategic media planning and buying, precision marketing, retail and digital commerce, branding, experiential, public relations, healthcare marketing and other specialty marketing services to over 5,000 clients in more than 70 countries. For more information, visit www.omnicomgroup.com.

About Interpublic

Interpublic (NYSE: IPG) (www.interpublic.com) is a values-based, data-fueled, and creatively-driven provider of marketing solutions. Home to some of the world’s best-known and most innovative communications specialists, IPG global brands include Acxiom, Craft, FCB, FutureBrand, Golin, Initiative, IPG Health, IPG Mediabrands, Jack Morton, KINESSO, MAGNA, McCann, Mediahub, Momentum, MRM, MullenLowe, Octagon, UM, Weber Shandwick and more.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This press release includes certain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the United States Private Securities Litigation Reform Act of 1995, as amended. All statements, other than statements of historical fact, included in this press release, including those that address activities, events or developments that Omnicom or Interpublic expects, believes or anticipates will or may occur in the future, are forward-looking statements. Forward-looking statements may be identified by words such as “anticipates,” “believes,” “continue,” “could,” “estimate,” “expects,” “intends,” “will,” “should,” “may,” “plan,” “potential,” “predict,” “project,” “would” or the negative thereof and similar expressions. No assurances can be given that the forward-looking statements contained in this press release will occur as projected and actual results may differ materially from those included in this press release. Forward-looking statements are based on current expectations, estimates and assumptions that involve a number of risks and uncertainties that could cause actual results to differ materially from those included in this press release. These risks and uncertainties include, without limitation:

• the risk that Omnicom or Interpublic may be unable to obtain governmental and regulatory approvals required for the merger (and the risk that such approvals may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the merger);
• the risk that the expiration of the HSR waiting period in connection with the previously announced Request for Additional Information and Documentary Material (Second Request) from the U.S. Federal Trade Commission (FTC) may not occur as anticipated, affecting the timing of completion of the merger;
• the risk that an event, change or other circumstance could result in the termination of the merger;
• the risk that a condition to closing of the merger may not be satisfied;
• the risk of delays in completing the merger;
• the risk that the merger may not qualify as a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended, as intended;
• the risk that the businesses will not be integrated successfully or that the integration will be more costly or difficult than expected;
• the risk that the cost savings and any other synergies from the merger may not be fully realized or may take longer to realize than expected;
• the risk that any announcement or news coverage relating to the merger could have adverse effects on the market price of Omnicom common stock or Interpublic common stock;
• the risk of litigation related to the merger;
• the risk that the credit ratings of the combined company or its subsidiaries may be different from what the companies expect;
• the risk that management’s time spent on the merger and integration may reduce their availability for ongoing business operations and opportunities;
• the risk of adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the merger;
• the dilution caused by Omnicom’s issuance of additional shares of its capital stock in connection with the merger;
• adverse economic conditions or a deterioration or disruption in the credit markets;
• the risk of losses on media purchases and production costs;
• risks related to reductions in spending from Omnicom or Interpublic clients or a slowdown in payments by such clients;
• risks related to each company’s ability to attract new clients and retain existing clients;
• changes in client advertising, marketing, and corporate communications requirements;
• risks related to the inability to manage potential conflicts of interest between or among clients of each company;
• unanticipated changes related to competitive factors in the advertising, marketing, and corporate communications industries;
• unanticipated changes related to, or an inability to hire and retain, key personnel at either company;
• currency exchange rate fluctuations;
• risks related to reliance on information technology systems and risks related to cybersecurity incidents;
• risks and challenges presented by utilizing artificial intelligence technologies and related partnerships;
• changes in legislation or governmental regulations;
• risks associated with assumptions made in connection with critical accounting estimates and legal proceedings;
• risks related to international operations, including currency repatriation restrictions, social or political conditions and regulatory environment;
• risks related to environmental, social, and governance goals and initiatives; and
• other risks inherent in Omnicom’s and Interpublic’s businesses.

All of the forward-looking statements Omnicom and Interpublic make in or in connection with this press release are qualified by the information contained or incorporated by reference in the joint proxy statement/prospectus. For additional information, see the sections entitled “Risk Factors” and “Where You Can Find More Information” beginning on pages 32 and 197, respectively, of the joint proxy statement/prospectus.

Forward-looking statements are based on the estimates and opinions of management at the time the statements are made. Except to the extent required by applicable law, neither Omnicom nor Interpublic undertakes any obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise. You are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof.