Sir Martin Sorrell undergoing chemotherapy after tumor removal

Sir Martin Sorrell, Executive Director of S4 Capital's Digital Advertising Division Photo: Holly Adams/Bloomberg

Sir Martin Sorrell undergoes chemotherapy after suffering a heart attack successful surgery to remove a malignant tumor.

The head of publicity said that he was «recovering well» after surgery in February.

In a note to staff, he said: «As expected I was looking for the best medical advice. I have come to the conclusion that I should receive preventive treatment in the coming months.”

It is understood that Sir Martin, who is the Executive Chairman of Digital Advertising at S4 Capital, will receive a low dose of chemotherapy as a precautionary measure to prevent the return of cancer.

The head of the advertising department said he expected to be able to work as usual most of the time. However, he decided to shorten his travel schedule for the next few weeks.

Sir Martin, 78, founded S4 Capital in 2018 after abruptly leaving WPP, the advertising giant he built from a shell company. than three decades ago.

Since then, he has rapidly expanded S4 through a series of acquisitions, including digital media companies MediaMonks and MightyHive.

The company now employs approximately 8,900 people worldwide, with 70% of its revenue coming from the Americas.

On Monday, the group released a memo from Sir Martin to employees addressed to «all S4 monks.»

Sir Martin wrote: “My doctors advised me during this treatment to be able to work as normal most of the time with full interaction with the company and our excellent executive team, although I also decided to shorten my travel schedule by a few weeks.

«Otherwise, work as usual. As always, thank you for your continued support and let me know how I can help you in any way I can.»

S4 ran into accounting problems last year after its finance department struggled to go keeping pace with rapid expansion. .

Over the past year, the shares have fallen by 50%, and the company's market value has fallen to 900 million pounds.

The company has previously stated that it has a succession plan in place in case Sir Martin retires, but did not provide any further details.