Regulatory Green Light: Omnicom–IPG Merger Cleared by UK Watchdog
The Competition and Markets Authority gives its approval, bringing Omnicom’s $13.25bn acquisition of Interpublic Group one step closer to completion, and ushering in a new era of ad consolidation.
In a landmark moment for the global advertising and marketing services industry, Omnicom Group’s $13.25 billion all-stock acquisition of Interpublic Group (IPG) has received clearance from the UK’s Competition and Markets Authority (CMA). This regulatory milestone not only moves the deal closer to completion, but also cements the direction of travel in the sector: scale, synergy, and global consolidation.
With the merger already approved by regulators in the US, Australia, India and elsewhere, CMA’s decision further clears the path for a transaction that will create the world’s largest advertising holding company overtaking WPP and Publicis in the process.
The CMA Decision: Phase 1 Clearance Granted
On 6 August 2025, the UK’s CMA confirmed that it would not escalate the Omnicom-IPG deal to a Phase 2 investigation. The competition watchdog concluded that the merger would not lead to a substantial lessening of competition in the UK advertising market.
The CMA’s original inquiry began in mid-June, with a statutory deadline of 13 August to complete Phase 1. That timeline has now been brought to a close, giving Omnicom and IPG further regulatory certainty.
A Global Wave of Regulatory Approvals
The UK is not the first major market to green-light the deal. In June 2025, the US Federal Trade Commission (FTC) gave its approval under a consent order that prevents the combined entity from coordinating political ad spend based on ideology or party alignment. Australia’s competition authority followed suit in July, concluding that the merger posed minimal risks to local advertisers and media owners.
Other countries to approve the deal include:
India, via the Competition Commission of India (CCI)
Brazil, through CADE
Singapore, New Zealand, and Japan
Clearance from China’s SAMR is reportedly in the final stages, with no significant objections expected.
Industry Implications: Creating a Global Giant
Should the merger complete as expected in the second half of 2025, it will create the world’s largest advertising and marketing holding company by revenue, staff count and geographic reach.
What the deal means:
Combined Revenue: An estimated $44–46 billion annually, overtaking WPP
Workforce: Over 130,000 employees across 120+ countries
Agency Networks: Integration of Omnicom’s DDB, BBDO and TBWA with IPG’s McCann, FCB and MullenLowe
Technology & Data Assets: Consolidation of precision marketing, analytics and programmatic buying platforms
Omnicom CEO John Wren has described the deal as “transformative,” with plans to deliver around $750 million in annual cost synergies through shared infrastructure, reduced duplication, and expanded use of AI-driven tools for media and creative delivery. “
The scale and depth of talent across both organisations positions us to deliver best-in-class outcomes for global clients while unlocking significant operational savings.”
Market Reaction: Competitive Jockeying
The deal has prompted a range of responses across the advertising sector. WPP, currently the largest holding company by revenue, has maintained that it is focused on “organic growth and strategic AI investment” rather than reactive M&A.
Publicis, which has pursued aggressive acquisitions over the past decade, including Epsilon and Sapient, is now seen as potentially considering its own defensive moves.
Independent agencies, meanwhile, are likely to face increased pricing pressure, as clients weigh the cost efficiencies of global networks against the perceived flexibility and specialisation of smaller firms.
There are also concerns among clients and regulators alike about concentration of media buying power. The merger will give Omnicom-IPG significant negotiating leverage with tech platforms such as Google, Meta, Amazon, and TikTok. Industry analysts suggest this could affect rates, ad placement dynamics, and even algorithmic preference.
Structural Impact: Integration Challenges Ahead
While the deal appears destined to close, significant challenges remain on the integration front.
Key risks include:
Cultural alignment between two very different organisational styles
Agency brand management, as overlap between networks such as FCB and DDB could require rationalisation
Client conflicts, with both groups servicing global brands across automotive, FMCG, pharma, and financial services
Technology stack harmonisation, especially in programmatic platforms and martech offerings
Despite these hurdles, Omnicom has a track record of successful large-scale integrations, including its 2016 acquisition of health marketing firm BioPharma, and IPG has long been praised for its disciplined financial management.
Timeline and Next Steps
With the UK CMA and other key regulators on board, the final outstanding jurisdictions are expected to issue rulings by September 2025. Subject to those approvals, the merger is slated to complete in Q4 2025.
Clients have been informed via account briefings, with assurances that agency relationships and scopes of work will be honoured throughout the integration period. Analysts expect organisational changes to begin surfacing in early 2026, particularly in shared service functions such as finance, HR, IT and media operations.
A Reshaped Global Landscape
The Omnicom–IPG merger is a defining moment for the advertising industry. It reflects broader pressures: the rise of generative AI, the need for global consistency in omnichannel campaigns, and the challenge of managing costs in an increasingly fragmented media ecosystem.
While clients and competitors may view the deal with caution, its regulatory progress and financial rationale are undeniable. Whether the merger leads to genuine innovation or simply further consolidation remains to be seen—but the scale and ambition of the move is unmistakable.