Early movers: NRG, P, UNH, GNC, AN, COH, UA & more
Traders work on the floor of the New York Stock Exchange on February 3, 2014.

Under Armour –The athletic apparel retailer's shares were upgraded to "buy" from "hold" at Jefferies, based on strong secular sales trends and a recent drop in the stock.

Pandora –The online radio service could be among the companies affected by news that the Justice Department will reexamine agreements with music licensing firms ASCAP and BMI. The increase in use of digital media has prompted the possible revision of those agreements, and that could eventually results in an increase in music royalty rates .

UnitedHealth –The health insurer raised its quarterly dividend by 34 percent to 37-1/2 cents per share, and also approved a share repurchase program of 100 million shares.

Check out which companies are making headlines before the bell:

Coach –The stock was downgraded to "neutral" from "buy" at Sterne Agee, which cited lackluster sales trends and lower probability of a North American turnaround.

Protective Life –The life insurer agreed to be bought by Japan's Dai-ichi Life Insurance for $5.7 billion, or $70 per share. It's the largest ever acquisition by a Japanese insurance company.

Newell Rubbermaid –Morgan Stanley upgraded the household products maker's stock to "overweight" from "equalweight," saying an improvement in sales is not yet priced into the stock.

AutoNation –The vehicle retailer reported a 15 percent increase in May sales compared to the same month a year ago.

GNC –The health products retailer is rated "buy" in new coverage at Bank of America/Merrill Lynch, based on improving comparable store sales trends.

Annie's –The organic food maker's auditor, PriceWaterhouseCoopers, is resigning from that duty. That comes after the auditor found a "material weakness" in the latest annual report related to an "insufficient complement of finance and accounting resources." That weakness, however, did not result in any material misstatements, according to the company.

Mattress Firm –The company posted first quarter profit of 31 cents per share, excluding certain items, missing estimates by five cents. However, the mattress retailer did raise its full-year sales forecast on stronger trends, and backed its prior full-year earnings forecast.

Tibco Software –Tibco projected quarterly profit of 12 to 13 cents per share, below Street estimates cents, with revenue also falling below current estimates, as sales of its Spotfire analytics software come up shy of forecasts.

NRG Energy –The energy firm is reportedly close to buying the largest wind farm in North America, Alta Wind Energy Center, for $800 million. The Wall Street Journal said the deal could be announced as soon as today.

Gartner – Chief financial officer Chris Lafond is leaving the information technology research firm at the end of the month to pursue other opportunities. He's served as CFO since 2003.

Ascena Retail Group –Ascena earned 27 cents per share, excluding certain items, for its third quarter, eight cents above estimates. However, the company formerly known as Dress Barn did see comparable store sales that were short of estimates, as is its sales guidance for the full year.

Monster Beverage –Credit Suisse began coverage of the beverage maker's stock with a rating of "outperform"

—By CNBC's Peter Schacknow

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