See coverage of the same story by greg1usa here.

After all that foreplay, Microsoft is walking away from Yahoo!. It's like a Facebook breakup. So is MS really just not that into Yahoo!, or is this a ploy to get Yahoo! to fall in love with MS, playing on Yahoo!'s insecurity and self-worth issues? Junior High is such a nightmare. And so is Silicon Valley.

Microsoft chief executive Steve Ballmer formally withdrew the offer in a letter to Yahoo chief executive Jerry Yang.

Mr Ballmer said Microsoft had raised its original offer from $44.6bn to $47.5bn (£24.1bn) - $33 per share.

But he added that Yahoo had insisted on at least $53bn, or $37 a share - more than Microsoft was prepared to pay.

The software giant had wanted to do a deal to be able to compete with Google, which dominates the lucrative market for internet advertising

In his letter to Mr Yang, which has been posted on the Microsoft website, Mr Ballmer said: "We continue to believe that our proposed acquisition made sense for Microsoft, Yahoo and the market as a whole. "Despite our best efforts, including raising our bid by roughly $5bn, Yahoo has not moved toward accepting our offer.

"After careful consideration, we believe the economics demanded by Yahoo do not make sense for us, and it is in the best interests of Microsoft stockholders, employees and other stakeholders to withdraw our proposal."

Source: news.bbc.co.uk