(Bloomberg) -- S4 Capital Plc Executive Chairman Martin Sorrell is recovering after undergoing a minimally invasive surgery in London on Sunday evening, the marketing mogul said.

“I want to let you know that I had successful keyhole surgery last night,” the WPP Plc founder said in a statement Monday. “I am making an excellent recovery, and I expect to be in hospital for a few more days and make a full and rapid recovery from the surgery, thereafter.”

Sorrell, 77, said S4 will run as usual and he continues to be “actively engaged,” including contact with the board and senior management. 

A representative for S4 declined to comment on the reason for the surgery.  

Sorrell was the founder of WPP, which he built into the largest advertising company before resigning in 2018 following allegations of misconduct, which he denied. 

The agency group said at the time the investigation “did not involve amounts that are material” and he left as a so-called good leaver, according to WPP’s 2018 annual report. 

He opened S4 Capital soon after as a rival group, which Sorrell has also built through serial acquisitions. Sorrell has focused on what he calls the “new age, new era” of digital marketing.

(Updates with S4 declining to comment and additional context)

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