(Read More: See the Day's Top Percentage Winners & Losers)
Northern Trust - The bank earned $0.67 per share for the first quarter, five cents below estimates, with revenues also falling short.
Costco Whoelsale, Wal-Mart Stores, Target - UBS has initiated coverage on the three retailers, rating Costco and Wal-Mart "buy" and Target "neutral."
Sprint Nextel - A day after Sprint received a $25.5 billion takeover bid from Dish Network, JPMorgan Chase upgraded the shares to "overweight" from "neutral."
Microsoft - Morgan Stanley has upgraded Microsoft to "overweight" from "equal weight," saying the market is overlooking several earnings catalysts amid disappointment about adoption rates for Windows 8.
Netgear - The network equipment maker issues an estimated first-quarter forecast below Street estimates. Netgear said shipments of new storage products were less than it had planned.
HCA - HCA also announced a preliminary first-quarter estimate that was below Street forecasts. The nation's largest for-profit hospital operator pointed to a slowdown in admissions growth, as well as weaker outpatient volumes.
Mack-Cali Realty - Mack-Cali is cutting its quarterly dividend by 33 percent in an effort to save cash. The payout will now be $0.30 per share compared to the prior $0.45, a move that will save more than $13 million per quarter. The real estate investment trust said weak demand for office space is impacting its business.
U.S. Airways - The airline and American Airlines parent AMR have filed papers detailing how their merger agreement was negotiated, a step that U.S. Airways CEO Doug Parker said was significant in moving towards completing the deal.
Forest Laboratories - Forest Labs and Spanish partner Almirall said phase-3 clinical trial results for a new inhaler known as Genuair were positive. If the next round of testing has similar results, new drug applications will be filed with authorities in both the U.S. and Europe.
Macy's - The retailer will appeal a judge's interim ruling that rival J.C. Penney can continue to sell unbranded Martha Stewart-designed goods in its stores, while a legal battle continues. A judge ruled last week that the goods could remain on Penney shelves as long as they don't display Stewart's name.