Check out which companies are making headlines after the bell Tuesday:
Clearwire - Dish Network offered to acquire the wireless communications company at $3.30 a share. Back in December, Sprint said it would acquire a 50 percent stake in Clearwire it does not already own for $2.97 a share.
(Read More: Stocks End Lower Ahead of Earnings; Telecoms Sag)
Alcoa - The aluminum producer posted earnings of 6 cents a share, excluding one-time items, matching expectations, while revenue was $5.90 billion, topping expectations for $5.60 billion. The company added that it expects a 7 percent growth in global aluminum demand in 2013, up from 6 percent in 2012. Shares gained in extended-hours trading.
United Tech - The conglomerate reaffirmed its full-year 2013 outlook, saying it expects to post earnings of between $5.85 a share and $6.15 a share and revenue of between $64 billion and $65 billion, largely below Wall Street consensus. Shares edged lower in extended-hours trading.
Apollo Group - The for-profit education company posted earnings of $1.22 a share, excluding one-time items, on revenue of $1.06 billion, topping expectations for 90 cents a share on sales of $1.03 billion. Meanwhile, the company reported lower student sign-ups for the third-straight quarter and handed in full-year 2013 revenue guidance that was slightly below expectations. Shares dropped after an initial spike in extended-hours trading.
Orbitz - The travel website's CFO Mitch Marcus resigned after being at the post for just two months.
Seagate - The hard disk drive manufacturer said it expects to see "at least" $3.6 billion in revenue in the second quarter, beating expectations for $3.53 billion, sending shares higher in extended-hours trading.
Global Payments - The payment processing company posted earnings of 93 cents a share on revenue of $589 million, topping expectations for 87 cents a share on revenue of $575 million. The company also boosted its 2013 earnings guidance, matching Wall Street expectations. In addition, the firm approved up to an additional $150 million in stock buyback. Shares edged higher in extended-hours trading.
Navistar - R.W. Pressprich & Co initiated coverage of the truck and diesel engine parts provider with a "speculative buy" rating.