If Mayer decides to chart a completely new direction, she will need the approval of Yahoo's board. The directors include a major shareholder, New York hedge fund manager Daniel Loeb, who stands to be one of the biggest winners from an Alibaba payday. Loeb's fund, Third Point LLC, owns a 5.8 percent stake in Yahoo. Yahoo shareholders have grown increasingly frustrated as the company's revenue and stock price have flagged, even as advertisers shifted more of their marketing budgets to the Internet. Most of that money, though, has been flowing to Google, the Internet's search and video leader, and online social networking leader Facebook Inc. To compound investor exasperation, Yahoo squandered an opportunity to sell itself to Microsoft Corp. for $33 per share in May 2008. Yahoo shares fell 55 cents, or 3.4 percent, to $15.46 in extending trading Thursday, leaving them slightly below their level before Mayer was hired.