A new player has entered the Microsoft-Yahoo epic, the Wall Street Journal reports: billionaire investor Carl Icahn. He has bought about a 4% stake in Yahoo since Microsoft withdrew its offer to buy on May 3. Icahn will decide by tomorrow whether to launch an attempt to take over Yahoo's board and perhaps force a sale.
Hedge-fund managers are also watching Icahn's efforts, the Journal notes, as they decide whether to join a fight—even though there's no assurance Microsoft would make another offer. Though a Yahoo spokesman had no comment, sources told the Journal its leaders are confident they have enough investor backing to fend off such a challenge. (Read more Carl Icahn stories.)