"The breakdown in the talks is likely to send Yahoo's shares plunging, and Mr. Yang and his team will have to decide how to placate investors," reported New York Time Sunday morning.

Monday morning before the markets open Bloomberg reported "Yahoo, the Web company that spent three months fighting a takeover by Microsoft, tumbled $6.37 to $22.30. The software maker said this weekend it walked away when Yahoo demanded $37 a share. Microsoft had increased its $44.6 billion bid by about $5 billion to $33 a share. Microsoft shares added $1.27 to $30.51. "

"I am disappointed that Yahoo! has not moved towards accepting our offer," wrote Microsoft CEO Steve Ballmer yesterday in what must be one of the great understatements of all time. "But clearly a deal is not to be." The words came in a letter sent to Yahoo!'s CEO and Chief Yahoo!, Jerry Yang. "We continue to believe that our proposed acquisition made sense for Microsoft, Yahoo! and the market as a whole," Ballmer noted, even as he announced that Microsoft has now officially withdrawn its proposal to acquire Yahoo! Inc.

"Despite our best efforts, including raising our bid by roughly US$5 billion, 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," wrote Ballmer.

"We have a talented team in place and a compelling plan to grow our business through innovative new services and strategic transactions with other business partners. While Yahoo! would have accelerated our strategy, I am confident that we can continue to move forward toward our goals," Ballmer added.

"We are investing heavily in new tools and Web experiences, we have dramatically improved our search performance and advertiser satisfaction, and we will continue to build our scale through organic growth and partnerships," said Kevin Johnson, Microsoft president for platforms and services, in an accompanying statement released by Microsoft.

Read the full text of Ballmer's letter

• Is Yahoo! Too Large a Company to Force into Microsoft's Ways?
• Microsoft-Yahoo! - Microsoft Threatens To Walk
• Microsoft-Yahoo! - Microsoft Fails To Make Up Its Mind What To Do Next
• Microsoft-Yahoo - Yahoo Dodges the Takeover Bullet As Microsoft Calls Off Bid
• Microsoft Will End Up Buying Yahoo Anyway