Nov. 7 (Bloomberg) -- Yahoo! Inc. fell 13 percent in Nasdaq trading after Microsoft Corp. said it has no interest in acquiring the Internet company.

Yahoo Chief Executive Officer Jerry Yang said this week the Internet company is willing to sell, fueling investor speculation that Microsoft might bid for all or part of Yahoo. Microsoft has ``moved on,'' and isn't planning another offer, CEO Steve Ballmer said today at a conference in Sydney.

``We're not interested in going back and re-looking at an acquisition,'' Ballmer said. ``I'm sure there are still opportunities for some kind of partnership around search.'' He didn't elaborate on the potential partnerships.

Yahoo dropped $1.76 to $12.20 at 4 p.m. in Nasdaq Stock Market trading. Yang had said he is ``open to everything'' after Google Inc. backed out of a proposed online-advertising partnership, narrowing his options for turning around Yahoo. The remarks pushed the shares up as much as 7 percent yesterday.

Yang rejected bids of as much as $47.5 billion, or $33 a share, earlier this year.

``To this day, I would say that the best thing for Microsoft to do is to buy Yahoo,'' Yang said Nov. 5 at a conference in San Francisco. ``I don't think that is a bad idea at all.''

Yahoo's Options

Yahoo spokesman Brad Williams yesterday reiterated Yang's remarks. He declined to comment on whether Sunnyvale, California- based Yahoo would seek to start new negotiations.

``We're open to talking to them,'' Williams said. ``We still believe acquiring Yahoo is the best option for Microsoft.''

Yahoo sought the partnership with Google, the most popular search engine, as a way to bolster sales. Yahoo's revenue growth, excluding sales shared with partners, slowed to 3 percent last quarter, down from 14 percent a year earlier. Yang faced threats of a proxy fight with billionaire investor Carl Icahn and dissatisfaction from investors, who withheld about a third of their votes for Yang's re-election to the board in August.

Besides a deal with Redmond, Washington-based Microsoft, Yahoo's other option is to pursue an acquisition of Time Warner Inc.'s AOL. Buying AOL wouldn't give Yahoo the same payoff as the agreement with Google, said Jeff Lindsay, an analyst at Sanford C. Bernstein & Co. in New York.

To contact the reporter on this story: Dina Bass in Seattle at dbass2@bloomberg.net; Shani Raja in Sydney at sraja4@bloomberg.net

Last Updated: November 7, 2008 16:32 EST