Martin Sorrell's resignation triggers 7% slide in WPP shares

Market reacts to uncertainty over succession at world’s largest advertising businessWPP: breaking up world’s top advertising group could net £22bnSir Martin Sorrell’s abrupt resignation from WPP triggered a 7% slide in the group’s share price on Monday as investors mulled the uncertain future of the world’s largest advertising business.Sir Martin, who founded WPP 33 years ago, resigned with immediate effect on Saturday amid an investigation into allegations of