WPP’s not only losing Mark Read, it’s about to lose another client to Publicis: Mars

That leaves WPP Media without an account valued at $1.7 billion, per agency tracker COMvergence — and marks yet another blow to its client roster, coming just months after Coca-Cola handed $800 million in North American media billings to Publicis.

The shakeup stems from a sweeping review of Mars’ agency model, launched last fall. Everything outside of creative has been on the table — media, production, social, connected commerce, brand PR and even influencer marketing. Whether Omnicom, which still handles Mars’ creative, will pick more of the business remains to be seen. 

What is clear is this: the original expectation, according to a source with knowledge of the process, was to pare down three holding companies — WPP (media), Publicis (commerce) and IPG (PR) — to two. Though Mars never confirmed that plan publicly, it was a clear undertone in the pitch. Somewhere along the way, that calculus shifted. 

WPP declined to comment, as did Publicis and Omnicom, another finalist in the review. Mars did not immediately return a request for comment.

The timing won’t be lost on industry watchers: Mars’ move comes just as WPP CEO Read announced he’ll step down at the end of the year, capping a seven year tenure during which WPP’s market cap has fallen by half to roughly $6 billion. And the holding company has lost more clients than it has gained.

Despite restructuring the business, forging partnerships with firms like Nvidia and making strategic acquisitions like InfoSum, Read couldn’t steer WPP clear of the broader storm: a volatile ad market, pandemic fallout, cultural headwinds and deep structural shifts in the agency world. It all came to a head last year when WPP lost its crown as the world’s largest ad agency holding company by revenue — to none other than Publicis. 

Read publicly acknowledged all these challenges but insisted WPP was on the right track, with AI at the center of its next chapter. But for some CMOs, the progress felt too slow — especially as Publicis kept buying its way into growth with acquisitions like Influential, Captive8 and Lotame, while Omnicom and IPG moved toward a mega-merger poised to reshape the U.S. ad market.

WPP, by comparison, lacked a compelling narrative. That may be changing with the return of GroupM veteran Brian Lesser to lead its media businesses, the rollout of its in-house AI platform and a renewed push for operational efficiency. But there are still a lot of ifs, buts and maybes that need to fall into place before that story sticks.

“Lesser and WPP Media need room to execute their strategy for building their leadership, consolidating their media operations and to fully implement Open Media Studio,” said Jay Pattisall, vp and senior agency analyst at Forrester.

“Holding companies were built on the promise of scale,” said Marcy Samet, a former holdco exec who now runs her own growth consultancy for agencies called the LBRB COLLECTIVE. “But scale without cohesion, direction, and measurable growth is not a strength. It’s a liability. Creative wins don’t always mean the business is thriving. AI claims don’t mean transformation is real. And being everywhere doesn’t mean you’re focused where it counts.”