Martin Sorrell is "making an excellent recovery" after undergoing keyhole surgery at a London hospital.
The S4 Capital executive chairman and WPP founder, who turns 78 on February 14, underwent an operation on Sunday night.
In a statement issued to the stock market, S4 said that the operation had been a success.
The statement continued with a personal note from Sorrell addressing "all S4 Monks" --- a reference to S4's MediaMonks --- with an update on his convalescence.
"I want to let you know that I had successful keyhole surgery last night. 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. During this period, S4 will run as usual, and I will continue to be actively engaged," he said. "I remain in contact with the board and the senior management team in all the usual ways and thank them for their support."
Sorrell ran WPP for 33 years, before departing in April 2018 and launching S4 Capital soon afterwards.
This story first appeared on campaignlive.co.uk.