3 execs who sold their company to Martin Sorrell’s S4 Capital are suing, alleging they’re owed millions

Martin Sorrell's S4 Capital is being sued by three former employees.

Xavi Torrent/Getty Images for Cannes Lions Three execs who sold their company to Martin Sorrell's S4 Capital are suing the ad firm.

The lawsuit alleges they're owed millions of dollars and shares.

S4 declined to comment on ongoing litigation.

Three executives who sold their company to S4 Capital are suing the agency group helmed by advertising mogul Martin Sorrell , alleging it has withheld millions of dollars and shares owed to them.

The former CitrusByte execs allege in the lawsuit that S4 engaged "in a campaign of obfuscation and delay" and raised "unfounded claims and arguments" to avoid payment, allegedly withholding at least $7 million in escrow funds and delaying or withholding millions of S4 shares tied to the deal.

S4 declined to comment on ongoing litigation.

The company has not made a legal response to the claims in the lawsuit, which was filed earlier this month.

UK-based S4 was launched in 2018 by Sorrell, following his acrimonious exit from WPP , where he had served as CEO for more than 30 years.

The company, which focuses on digital marketing, grew in size rapidly through more than 20 acquisitions in its early years.

S4 acquired CitrusByte, a tech consulting firm later known as TheoremOne, in 2022.

It sits within S4's Monks Technology Services division.

The lawsuit highlights the friction in Sorrell's empire-building strategy, in which S4 typically acquires agencies and tech businesses for a mix of cash, stock, and future earnouts.

A public court battle risks creating a distraction and could complicate future deals at a time when it's trying to turn around its business.