Microsoft Corp Chief Executive Steve Ballmer said on Thursday the only discussion he's had with Yahoo Inc's top executive was a single phone call, but is holding out hopes for further talks.

Yahoo CEO Carol Bartz took the reins in January, succeeding co-founder Jerry Yang who beat back Microsoft's effort to buy the Internet company for $47.5 billion. Ballmer still covets a search partnership with Yahoo.

Unless I'm fooling myself, over time I would expect a there's a good opportunity for a deal, Ballmer said in response to a question from the moderator about the likelihood of such a partnership.

Shares of Yahoo rose more than 4 percent in morning trade.

Bartz has said that every business in Yahoo is up for examination as the company seeks to revive growth and compete with Internet search advertising leader Google Inc.

She has also opened the door to negotiations with Microsoft about a search partnership.

But if the two companies do discuss a deal, we're going to negotiate as companies negotiate, privately, Bartz said at a recent conference in San Francisco.

Microsoft's Ballmer expects to continue last year's pace of acquisitions and would do as many as 20 small deals this year ranging in value from $10 million to $500 million.

Yahoo shares were trading at $13.95, up 53 cents, on Nasdaq. Microsoft shares were up 7 cents at $17.03.

(Reporting by Anupreeta Das; Editing by Derek Caney)

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