Year in Review: How Omnicom’s IPG takeover made a new ‘big 5’ (or should that be 2?)

But this year, everything changed. Announced at the tail end of 2024, the industry spent most of the year holding its breath for Omnicom’s takeover of its fellow New York-headquartered holding company, IPG. When the deal closed in November of this year, that turned the Big Six into a Big Five – or did it?

Because the year didn’t just contain the slow closure of Omnicom’s IPG takeover. It also contained strong rumors that Tokyo-headquartered Dentsu is looking to divest its international holdings and was an annus horribilis for the already beleaguered WPP that saw the London-based firm fall out of the FTSE 100.

All that change prompted Jay Pattisall, Forrester’s principal agency analyst, to tell The Drum upon the closure of the Omnicom-IPG deal that “the big six global agencies are becoming the big three: Omnicom Group, Publicis Groupe and a WPP variant.”

Some might go even further: that WPP share price tailspin has taken its market capitalization all the way down to around $4.8bn, pulling it far closer to those of the already smaller Havas ($1.8bn) and below Dentsu ($5.6bn). (WPP might argue that share price isn’t everything; it hopes that chief executive Cindy Rose’s big AI bet and four-point plan will raise those numbers again soon.)

In comparison, a surging Publicis ($26.3bn) and an IPG-bolstered Omnicom ($25bn) may look to some, for now at least, like advertising’s Big Two.

• WPP’s Year in Review

Two became one: A condensed takeover timeline

December 2024: The deal is announced, with parties expecting it to close “in the second half of 2025.”

January 2025: The two firms’ top bosses sit down with The Drum to outline their vision of a new kind of holding company.

April 2025: As the deal works its way through the courts, Wren rubbishes talk of losing clients and talent to the likes of the surging Publicis as “nonsense fed by competitors.”

June 2025: The deal clears its first major regulatory hurdle as the US Federal Trade Commission approves it (with some caveats).

September 2025: The FTC’s comment period ends and Omnicom and IPG finalize their agreement with the regulator.

November 2025: As the deal nears completion, IPG posts poor final financial results and news of job cuts in the year-to-date. The deal clears its final regulatory hurdle as the European Commission approves it. Speculation builds that storied agencies are to be axed in the post-takeover merger as the likes of Alex Lubar, DDB boss, announce resignations. On November 26, hours before the US celebrates Thanksgiving, the deal formally closes.

December 2025: Freshly back from Thanksgiving, the new Omnicom’s structure comes into view as it announces a new structure that does indeed trim historic agency brands, including DDB, FCB and MullenLowe. More job losses, it announces, are underway.

• A full timeline of Omnicom’s takeover of IPG, on the day it closed

The challenge ahead

On deal day, Omnicom became the presumptive biggest holding company in the world (at the time of writing, as above, Publicis has a greater market cap). Analysts were quick to point out the challenge ahead in which scale and savings are not sufficient for success: Ewan McIntyre, analyst and chief of research at Gartner, told The Drum: “Size is impressive, but it’s not enough on its own – especially now… Omnicom and IPG need to show they’re more than just a cost-cutting story. That means investing in their data and AI capabilities, making sure their creative and strategic talent feels valued (not just like a line item to be trimmed) and being transparent about how the merger is actually going to benefit clients.”

Around the same time, others were even more pointed: M&A expert Tim Rice told The Drum that the worst-case scenario for Omnicom could be even worse than the famously bad year just suffered by WPP: “That whole business has been on hold while they’ve spent six months trying to sort out a merger. It’s like part of the business is on fire and they didn’t even know who to talk to.”

For Omnicom, Publicis and WPP alike, a key battleground is data and AI. Back in October, in an interview with The Drum, Publicis head honcho Arthur Sadoun credited “booming demand for AI” when the firm bucked the holdco trend once again by lifting rather than decreasing its growth forecasts.

For Omnicom, front-and-center in every official release about its IPG takeover since the announcement last year has been getting its hands on IPG data shop Acxiom, which Interpublic paid $2bn for back in 2018. The new-look Omnicom will now be hastening to incorporate Acxiom into its existing data infrastructure, going toe-to-toe with Publicis, which bolstered its own identity-based approach to big data with the purchase of Lotame this year. (WPP is taking a slightly different angle, which it calls the ‘data-connectivity approach,’ undergirded by its own acquisition of InfoSum earlier this year.)

As for AI, there’s that booming bottom line for Publicis, a big bet on self-serve data offering Open Pro to open up new revenue streams for WPP and Omnicom’s Acxiom-bolstered Omni hoping to see some Publicis-shaped numbers soon.

Consolidation will be the other core goal for the new-look Omnicom as the market’s top players all look to for the efficiency and simplified shop-front that has worked so well for Publicis in the form of Publicis One.

As it cuts jobs, releases real estate contracts and divests from agency holdings, Omnicom has already touted $750m annual cost savings, but analysts warn that a positive story will be necessary too. As Gartner’s Ewan McIntyre told The Drum last month, “if Omnicom wants to keep that top spot – and really earn it – it has to use its new scale to innovate, not just to save money.” We’ll start to see the results of that in 2026.