"Excited about the next chapter," says John Wren as he seals the Omnicom-IPG merger

New Delhi: Calling it a “defining moment” for both the company and the industry, Omnicom Chairman and CEO John Wren has formally closed the group’s USD 13.5-billion all-stock acquisition of Interpublic Group (IPG), creating the world’s largest advertising and marketing holding company by revenue.

With the transaction now complete, Omnicom overtakes WPP at the global level and brings some of the biggest creative and media brands in the business into a single network powered by its Omni data and intelligence platform.

Under the deal terms, legacy Omnicom shareholders now own about 60.6% of the combined company, while IPG shareholders hold roughly 39.4%. The new Omnicom group is expected to post more than USD 25–26 billion in annual revenue and continues to trade on the NYSE under the ticker OMC.

“This is a defining moment for our company and our industry,” Wren said, announcing the close.

“With the completion of the deal, Omnicom is setting a new standard for modern marketing and sales leadership, creating stronger brands, delivering superior business outcomes and driving sustainable growth. We’re excited about this next chapter.”

The merger unites two deep agency stables that have often competed head-to-head for global and local mandates.

On the Omnicom side, the combined group now houses creative networks such as BBDO, DDB and TBWA; media operations including OMD, PHD and Hearts & Science; and specialist and PR brands such as BBDO Worldwide, TBWA\Worldwide, DDB Worldwide, Omnicom Media Group, OMD, PHD, Hearts & Science, FleishmanHillard, Ketchum and Porter Novelli.

From IPG, marquee agencies coming into the fold include McCann Worldgroup, FCB, MullenLowe, IPG Mediabrands (with UM and Initiative), R/GA, Huge, Deutsch, MRM, Weber Shandwick, Golin and Octagon, among others.

For global marketers, that creates a single holding company umbrella that can offer creative, media, digital, data, PR, shopper, sports and experiential services in almost every major market.

The combined group will continue with Omnicom’s current leadership at the top. Wren remains Chairman and CEO, while Phil Angelastro stays on as Executive Vice-President and Chief Financial Officer. Former IPG CEO Philippe Krakowsky and long-time Omnicom executive Daryl Simm take over as Co-Presidents and Chief Operating Officers.

Krakowsky, Patrick Moore and E. Lee Wyatt Jr. have also joined the Omnicom Board of Directors. The company has said it will announce the full leadership lineup for the merged organisation, including regional and practice heads, on December 1, 2025.

Behind the scenes, both groups have already been preparing for integration. IPG has cut more than 3,000 roles since the start of 2025, while Omnicom reduced roughly 3,000 positions through the end of 2024, as part of what management described as pre-merger streamlining.

Omnicom has guided investors to expect around USD 750 million in annual cost synergies from overlapping functions, back-office consolidation and simplified structures.

The coming together of Omnicom and IPG reshapes the global “super-holdco” order. The old “Big Six” holding groups are now effectively five: Omnicom in the lead, followed by WPP, Publicis, Dentsu and Havas.

For large multinational advertisers, the immediate upside is access to a more tightly connected stack: Omni and IPG’s Acxiom data asset, creative networks on both sides, and media buying clout across Omnicom Media Group and IPG Mediabrands. In theory, that allows brands to run integrated, data-driven campaigns from strategy to commerce under one global relationship.

At the same time, the consolidation raises classic worries about choice and client conflicts. The group will now house agencies that work on direct rivals in categories such as autos, telecom, FMCG, tech and financial services. Industry executives expect Omnicom to lean heavily on firewalled “conflict shops”, ring-fenced teams and separate P&Ls to keep competing mandates apart, but acknowledge that some global and local accounts may still move as marketers reassess their rosters.

For independent and mid-sized agencies, the merger opens a different kind of opportunity. As the new Omnicom evaluates overlapping brands and leadership roles, senior talent and dissatisfied clients could look to smaller, more agile outfits. Many independents are already pitching themselves as alternatives to what they describe as “mega-machine” structures, especially on digital, content and creator-led remits.
In India, the global headline of Omnicom overtaking WPP sits alongside a more nuanced reality.

On the creative side, the combined group now owns six major networks: BBDO India, DDB Mudra Group and TBWA India from the Omnicom side, and McCann Worldgroup India, FCB Group India and MullenLowe Lintas from IPG.

Each of these agencies has long-standing client relationships and strong brand equity. However, many industry veterans question whether all six can continue as fully independent networks with separate CEOs, creative chiefs and support functions, given the global push for efficiencies.

Omnicom has already created Omnicom Advertising Group (OAG) in India under Aditya Kanthy to oversee BBDO, DDB and TBWA, and the expectation is that IPG’s creative operations will gradually be brought under the same umbrella.

In the media sector, IPG Mediabrands and Omnicom Media Group have combined to move Omnicom–IPG into a stronger number two position in India. However, GroupM’s estimated 40% share of media billings is expected to remain intact for now.

The media arms, led by Amardeep Singh (IPG Mediabrands) and Kartik Sharma (OMG India), will be central to how the global synergy and data story plays out locally.

With EU, US and other key regulators on board and the transaction now closed, the integration challenge begins in earnest.

Over the next 12 to 18 months, Omnicom will have to decide which agency brands to retain, merge or sunset; how to allocate regional and local leadership roles; how to manage sensitive client conflicts; and how to deliver the promised USD 750-million cost savings without triggering a damaging exodus of talent or business.

For now, Wren is framing the deal as a bet on scale, data and AI-enabled marketing at a time when social platforms, retail media and commerce are rewriting the rules of brand building.

Whether the new Omnicom can turn that thesis into an advantage without dulling the creative edge of agencies like BBDO, TBWA, McCann, FCB and MullenLowe is the question the rest of the industry will be watching closely.