Sir Martin would of course assist with the transition.
"As I look ahead, I see that the current disruption we are experiencing is simply putting too much unnecessary pressure on the business, our over 200,000 people and their 500,000 or so dependents, and the clients we serve in 112 countries".
WPP said the investigation, which regarded financial impropriety, had concluded. It added that the 73 year old would be "treated as having retired" and that his share awards would be "pro-rated in line with the plan rules and will vest over the next five years, to the extent group performance targets are achieved".
Sir Martin's resignation will come 10 days after WPP said it had appointed independent counsel to investigate an allegation of personal misconduct against him.
Sorrell has resigned under a cloud and his PR Companies are working overtime to protect the reputation of the world's largest advertising and communications group.
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Congress senior leader Gulam Nabi Azad said, "The government is sleeping and so at this time Congress will have to wake them up. On Thursday midnight Congress called for a candle march protest at India Gate to show the outrage of the people.
Quarta said: "Sir Martin has been the driving force behind the expansion of WPP to create the global leader in marketing services".
Sorrell, who worked at Saatchi & Saatchi before founding WPP, said the company has been "a passion, focus and source of energy for so long".
City observers believe that WPP would want to conduct a full, external search process to find a new chief executive in the event that Sorrell departed.
He said that he leaves the company in "very good hands", with Read, Scott and the management team at all levels having the knowledge and abilities to take WPP to "even greater heights, as well as capitalise on the geographic and functional opportunities".
The world's biggest ad group chose to launch the investigation into its chief executive after a whistleblower made allegations.
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SHOWING THEIR SUPPORT , and very blue tongues, for Child Abuse Prevention Month are Pre-K students from Dew ISD. In other cases, however, the deaths are a result of "pure evil", a more hard problem to combat, he said.
Sorrell and his family trust also own a stake of about 1.8% in WPP, worth about £250m.
Roberto Quarta, the chairman, and Nicole Seligman, senior non-executive director and an experienced corporate lawyer, set up a board sub-committee to examine the claims through a formal process.
Several people who have attended WPP board meetings in the past identified Sol Trujillo, a former USA telecoms boss, as a non-executive director who sometimes asked the most challenging questions.
"If WPP does well, I do well", he told the Press Association in April 2016.
Sorrell, who will continue to be available to the board with his valued guidance signed off saying, "As a Founder, I can say that WPP is not just a matter of life or death, it was, is and will be more important than that".
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He has won five times in China , including past year , and has taken pole six times on the Chinese circuit. It's not what you want and it's easy to say afterwards "I should have waited".