Check out the companies making headlines after the bell Monday:
Yahoo shares jumped more than 3 percent after the media company said its board authorized it to spin off its Aabaco business, despite uncertainty surrounding the tax treatment of the transaction. Aabaco is a newly formed independent company that will hold Yahoo's remaining Alibaba Group stake.
IBM announced plans to purchase Meteorix, a service partner of human resource software provider Workday. IBM said the acquisition would help the companies gain a "new competitive advantage." Workday shares rose about 2 percent, and IBM was untraded after the bell.
Utility servicer Exelon said it would ask regulators to reconsider its plan to acquire electricity supplier Pepco. The D.C. public services commission rejected the merger in August. Pepco, which supports the request to reconsider, rose more than 2 percent after hours, while Exelon shares were flat.
Wearable camera manufacturer GoPro and navigation systems provider Garmin were both up more than 2 percent on news that Sterne Agee CRT initiated coverage of the firms with "buy" ratings. The company also initiated coverage of Apple, Samsung Electronics and Western Digital, also with "buy" ratings. Those stocks were largely untraded after hours.
Shortly before the closing bell, Facebook said some users experienced service outages " The social media company's shares were marginally higher after the bell.
Shares of the aluminum maker were up about 1 percent in extended-hours trading. Earlier, Alcoa said it would split into two companies holding its legacy business and engineered products unit.
Correction: An earlier version misstated the name of Sterne Agee CRT