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.