Sir Martin Sorrell has stepped down from WPP with

Sir Martin Sorrell has stepped down from WPP with immediate effect. Roberto Quarta, chairman of WPP, becomes executive chairman until the appointment of a new CEO.

The $20.8 billion British company owns big brands in the marketing and communications world, including Olgivy & Mather, Young & Rubicam and 400 others. The company has over 200,000 employees.

73-year-old Sorrell was largely responsible for growing WPP into the advertising empire, having founded the business in 1985. He remained at the helm for decades. Some of its biggest clients include Unilever and Procter & Gamble.

A spokesperson for WPP provided a statement, attributed to Sorrell which said, “Obviously I am sad to leave WPP after 33 years. It has been a passion, focus and source of energy for so long. However, I believe it is in the best interests of the business if I step down now.”

Sorrell will be available to assist with the transition. As per the official press release issued on the company site, «the previously announced investigation into an allegation of misconduct against Sorrell has concluded. The allegation did not involve amounts that are material.»