Yahoo is now considering a sale of its core business and the stock is popping

Yahoo is now considering a sale of its core business, instead of a spin off, according to a report by Bloomberg on Friday.

Yahoo stock is now up 3.5% following the report.

The report said that Yahoo hasn't hired a bank or contacted potential buyers, yet, citing anonymous sources, but noted that it represents a "shift in the internal thinking" about what to do with its core business.

Yahoo said in December that it was exploring a plan to spin off its core business into a separate publicly traded company. Yahoo's chairman stressed at the time that the company was not putting itself up for sale, though he acknowledged that Yahoo would have to entertain any offers it received.

The news comes on the heels of a letter activist shareholder Starboard sent to Yahoo's board, which urged "significant changes" in Yahoo's management, board, and strategy. The letter implied that Starboard would run a proxy fight if Yahoo didn't make these changes.

Yahoo's growth has stalled in recent years and investors are increasingly growing impatient with Yahoo CEO Marissa Mayer's performance. Excluding Yahoo's stake in its Asian assets, investors are essentially giving zero value to Yahoo's core business, which include its online content and advertising units.

According to Business Insider's Biz Carson, Yahoo is preparing to cut 10% or more of its workforce this month, as the company preps for a major organizational shake-up.

Wall Street analysts believe a sale of Yahoo's core business is inevitable at this point. Big media and communications companies like Verizon, AT&T, and Comcast are believed to be front-runners to buy Yahoo's core business, but some analysts believe it could be any large company with large amounts of user data.

Yahoo wasn't immediately available for this report.