WPP shares fall 6% as company, investors adjust to post-Martin Sorrell era

WPP entered uncharted territory on Monday after the exit of founder Martin Sorrell left the world's biggest advertising company rudderless at a time of intense industry change.

Shares in WPP fell 6 percent after Sorrell, the driving force behind 33 years of dealmaking and relentless expansion, stepped down on Saturday after the board investigated an allegation of misconduct.

David Herro of Harris Associates, WPP's biggest shareholder according to Thomson Reuters data, said Sorrell would be missed.

"Sir Martin is a visionary, a legend in advertising and a skilful businessman," he said. "The circumstances surrounding this are regrettable as is a leadership transition without Sir Martin's involvement.