The U.K.-headquartered ad network has posted disappointing earnings since the end of 2024. In Q1 2025, it reported a 5% dip in revenue and forecast flat to declining revenues for 2025. 

The company has been banking on its newly rebranded WPP Media division to turn its fortunes around. However, Mars is the third major client brief lost by WPP Media, and specifically EssenceMediacom, this year.

In March, the U.K.-headquartered agency giant lost Coca-Cola’s $700 million North America media business to rival Publicis, chipping away at its $4 billion relationship with the beverage giant. 

Then, at the start of June, Paramount fired WPP Media after two decades working together and hired Publicis. This changeup was not the result of a review and reportedly surprised many.

In a statement announcing his exit, Read said he is “leaving WPP with an exceptional leadership team and a secure financial position that allows [it] to face the future confidently and capture the opportunities ahead.”

A search for his successor is underway.