
Qi Lu, former head of search at Yahoo, recently joined Microsoft to head up its online operations, and Yahoo is currently looking for a new chief executive after the departure of Jerry Yang.
Reports on Friday suggest that the front runners for the Yahoo top job include Carol Barz, former chief executive of engineering software firm Autodesk, and current Yahoo president Susan Decker.
But if Ballmer is expressing renewed interest in buying Yahoo's search business, it represents a distinct change of heart from last year when he reportedly told attendees at the Committee for Economic Development that he was no longer interested in buying Yahoo or any part of it.
"We made an offer, we made another offer, it was clear Yahoo did not want to sell the business to us, and we moved on," he said at the time.
"We are not interested in going back and [reconsidering] the acquisition. They turned us down at US$33 a share; move on."
Microsoft could not immediately provide comment on the reports.