The acquisition, announced at the end of 2024, was finalised last week after regulatory approval from the European Union. 

Florian Adamski, chief executive of OMD Worldwide, has been appointed chief executive of Omnicom Media, including Hearts & Science, Initiative, Mediahub, OMD, PHD, UM and Acxiom.

Chris Foster, chief executive of Omnicom Public Relations, will oversee the integration of Omnicom’s PR and communications agencies with IPG’s communications businesses. His remit will cover FleishmanHillard, Golin, Ketchum, Porter Novelli and Weber Shandwick.

Sergio Lopez is appointed chief executive, Omnicom Production, including Content Solutions, Production Management and Studios.

Duncan Painter will be chief executive of advanced intelligence platform Omni and Flywheel Commerce Network.

As chief executive of Omnicom Advertising, Troy Ruhanen will oversee BBDO, McCann, TBWA and the U.S. Advertising Collective.

Michael Larson has been appointed chief executive of Diversified Agency Services, with reports including:

• Dana Maiman, chief executive, Omnicom Health, including healthcare professional & consumer, medical communications, patient engagement and managed markets
• Mark O'Brien, chief executive, Omnicom Branding, including Interbrand, Siegel+Gale, Sterling Brands, and Wolff Olins
• Luke Taylor, chief executive, Omnicom Precision Marketing, including Credera, Critical Mass and Rapp.

In addition, two enterprise-wide teams will focus on connected services at an Omnicom-wide level, with Jacki Kelley, chief client and business officer, and Andrea Lennon, client experience officer leading Omnicom’s Client Success Leaders. Omnicom's Global Growth Team will be led by George Manas, chief growth and solutions officer.

John Wren will continue as chair and chief executive of Omnicom, as previously announced, with Phil Angelastro as executive vice-president and chief financial officer, and Philippe Krakowsky and Daryl Simm as co-presidents and chief operating officers.

Wren said: "I am proud to welcome the people, agencies and clients of Interpublic to Omnicom and create a global community of the best and brightest professionals in the industry, all of whom will have access to the most advanced AI tools and Omni, our advanced intelligence platform. Together, we will be the go-to company that shapes how brands grow, people connect and culture evolves."