Traders work on the floor of the New York Stock Exchange.

RF Micro Devices –The chipmaker will merge with TriQuint Semiconductor in an all-stock deal that represents a 5.4 percent premium for TriQuint shareholders.

Verizon –The telecom giant said it would see higher margins this year, following the completion of its deal to buy the 45 percent of Verizon Wireless held by Vodafone . However, it also projected slightly slower revenue growth.

Check out which companies are making headlines before the bell:

Facebook–The social network's just-acquired WhatsApp suffered an outage over the weekend, which WhatsApp founder Jan Koum blamed on a network router. He issued an apology to the more than 450 million users of the mobile messaging service.

United Technologies–United Technologies will lay off 600 workers from its Sikorsky Aircraft unit over the next several weeks. The unit is citing "challenging and unstable economic conditions" that continue to affect the industry.

HSBC–The bank missed estimates with its latest earnings report, and said it will be impacted by greater volatility in emerging markets this year.

Las Vegas Sands–Chief executive Sheldon Adelson said the casino operator will spend "whatever it takes" to set up casinos in Japan. The company is hoping to win a casino license in that country if Japan does decide to open the country to casino gambling.

Boeing–Boeing machinists in St. Louis have approved a 7-1/2 year contract extension that shifts the workers from a pension plan to a 401(K) retirement savings arrangement.

Apple –The tech giant released a software update for its iOS devices over the weekend that dealt with an encryption failure, and promised an update "very soon" for its Mac computers. The issue makes it possible for hackers to access email and personal information. Separately, Apple and Samsung have failed to settle a long-running patent case through mediation, and will now square off in court next month.

BlackBerry–The company will offer its BlackBerry Messenger service to Microsoft's Windows Phone platforms this summer. Messenger will also be available for the soon-to-launch Nokia X platform. Separately, the Detroit News reports Ford has chosen BlackBerry over Microsoft as its partner on its Sync voice-activated system in future models.

Darden Restaurants–The restaurant chain is being called upon by hedge fund Starboard Value to put its Red Lobster spinoff plan to a shareholder vote, according to the Wall Street Journal. Starboard wants to restaurant operator to delay the planned spinoff.

Archer Daniels Midland–ADM said it would not accept crops from Syngenta that contain a new genetically modified corn trait until it is approved by major importers.

—By CNBC's Peter Schacknow

Questions? Comments? Email us at marketinsider@cnbc.com