Shares in Marie Claire publisher Future plunge as chief announces departure

More than 300m wiped off market value as company says Zillah Byng-Thorne is to step down

Future, one of Europe's biggest and most successful digital media companies, has seen more than 300m wiped off its market value after the company said that chief executive Zillah Byng-Thorne is to step down after almost a decade.

Byng-Thorne, who has made more than 35m transforming a magazine publisher facing collapse into a 1.7bn digital media empire, has told Future that she intends to step down by the end of the next year.