Traders on the floor of the New York Stock Exchange.

MeadWestvaco –Starboard Value reported a 5.6 percent stake in the packaging products company, calling it "deeply undervalued."

Mylan –The drug maker has settled patent litigation with Pfizer over Celebrex capsules, and will launch generic Celebrex no later than December.

–The chip maker is exploring strategic alternatives for its cellular baseband business, and has hired JPMorgan Chase in conjunction with that effort.

Check out which companies are making headlines before the bell:

General Motors—The automaker's board set to hold its monthly meeting amid the ongoing controversy surrounding its ignition switch recall. In addition, former U.S. Attorney Anton Valukas is expected to release his report on the recall this week.

Apple – The iPhone maker holds its annual Worldwide Developers Conference in San Francisco today, with the company expected to unveil new innovations such as home control software for the iPad and iPhone, as well as a new version of the iOS operating system.

Protective Life–The insurer is in talks to be bought by Japan's Dai-ichi Life for more than $5 billion, according to the Wall Street Journal.

Marathon Oil–The oil company is selling its Norwegian operations to Norway's Det Norske Oljeselskap for $2.1 billion.

ARC Healthcare–The real estate investment trust is being bought by Ventas for $2.6 billion in cash and stock. Both companies are REITs specializing in medical office buildings and senior living facilities.

Novartis–The drug maker has hired Merck executive Bruno Strigini to head its oncology unit.



Eli Lilly–The pharmaceutical giant's cancer drug ramucirumab extended survival in lung cancer patients, according to trial data presented over the weekend.

Google– The search giant reportedly plans to invest more than $1 billion in a series of internet access satellites around the globe, according to the Wall Street Journal.

Allergan–The eye care products company said it would consider the improved takeover bid from Valeant Pharmaceuticals, which came out during the trading day Friday. The latest offer is worth $53.8 billion in cash and stock.

Zillow–The real estate website operator's stock was cut to "sector perform" from "outperform" at Pacific Crest, which said it sees a less-attractive risk/reward profile and limited upside. RBC Capital also cut its rating on the stock to "sector perform" from "outperform."

—By CNBC's Peter Schacknow

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