It was once the world's leading search engine, its founders held talks about a merger with Rupert Murdoch's News Corporation - and it even managed to fend off a $44bn takeover bid by Microsoft. But Yahoo has put itself up for sale, after firing its chief executive of 18 months Carol Bartz by phone.

Her dismissal prompted what Yahoo said was a "comprehensive strategic review" to "position the company for future growth".

The problem for Yahoo is that it is being eaten alive by two upstarts, Google and Facebook, who are absorbing the advertising revenue it used to rely on. Yahoo's second-quarter results were its worst since 2005 and Henry Blodget, the former Wall Street analyst turned pundit, suggested on his Business Insider website that the firing of Bartz probably indicates that the current quarter is going no better - and possibly worse as companies chop their advertising budgets as the economic weather clouds over.