Stocks to Watch: RHT, AMD, MDVN & More

Check out which companies are making headlines after the bell Tuesday:

United Continental - United Airlines is facing a "network outage" issue affecting its operations at airports and its website. At 4:30pm ET, the Federal Aviation Administration issued a ground-stop for all United Airlines (including Express) for flights destined to Newark (90min) or San Francisco (30min), two of United's hubs. (Click here for extended-hours quotes.)

Red Hat - The software company said it has bought business process management (BPM) technology developed by Polymita Technologies. BPM is a management approach that helps a company's workflow. Financial terms of the deal have not been disclosed. (Click here for extended-hours quotes.)

AMD - The chipmaker announced it has hired John Gustafson as its Chief Graphics Product Architect. (Click here for extended-hours quotes.)

Medivation - The biopharmaceutical company announced a two-for-one forward split of its common stock. (Click here for extended-hours quotes.)

Sealed Air - The bubble-wrap maker announced CEO William Hickey will retire in March 2013. (Click here for extended-hours quotes.)

—By CNBC’s JeeYeon Park (Follow JeeYeon on Twitter: @JeeYeonParkCNBC)

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