Check out which companies are making headlines before the bell:
Royal Dutch Shell—Shell will buy BG Group for $70 billion in cash and stock. This is the first major oil company takeover deal since Chevron bought Texaco for $36 billion in 2000.
Tesla—The automaker announced an upgrade of its flagship Model S, featuring a larger battery pack and all-wheel drive.
Merck—Merck received a "Breakthrough Therapy" designation from the FDA for its investigational hepatitis C therapy.
Apple—Societe Generale downgraded Apple to "hold" from "buy," saying currency issues and difficult comparisons for handset sales could weigh on Apple shares.
Lululemon—Sterne Agee upgraded the yogawear maker's stock to "buy" from "neutral," saying investments in new systems and processes will pay off sooner and more than anticipated.
WebMD—Goldman downgraded the health website operator's shares to "sell" from "neutral," citing reduced opportunity for outperformance.
Rite Aid—The drug store chain earned an adjusted 14 cents per share for its latest quarter, doubling estimates, with revenue also above consensus. However, the company did give a full-year consensus below current Street estimates.
Xerox—Citi upgraded Xerox to "buy" from "neutral," pointing to a compelling valuation and increased opportunity for accretive acquisition deals.
Noble Energy—The oil and gas exploration and production company will cut about 220 positions, about half at Noble's Colorado operations.
Dave & Buster's—The entertainment venue operator reported adjusted quarterly profit of 33 cents per share, 5 cents above estimates, with the restaurant chain's revenue beating estimates as well. Revenue guidance was, however, on the conservative side.
Lionsgate—The entertainment company announced a secondary offering which will see MHR Fund Management sell 10 million common shares in the movie studio. Lionsgate will not receive any proceeds from the offering.
Pentair—The industrial manufacturing company cut fiscal first quarter guidance due to a stronger dollar, and slower than expected oil and gas industry shipments.
Mattress Firm—The mattress retailer said certain shareholders would sell more than 1.5 million shares of its common stock, including some members of management and the board of directors. The company won't receive any proceeds from the sale.
Rio Tinto—Australia's treasurer reportedly said he would not allow Britain's Glencore to buy the mining company, because of concerns over losing Rio's considerable tax revenue. Glencore had approached Rio last year but was rebuffed.
Novo Nordisk—The Danish drug maker was told by the FDA that the agency had accepted Novo's resubmitted application for its insulin drug Tresiba. The drug had originally been rejected by the FDA two years ago.
Dollar Tree—The Federal Trade Commission told Dollar Tree that it must divest 340 stores before it can complete its $8.5 billion takeover of rival discount retailer Family Dollar Stores. Dollar Tree said it expects almost all of those divested stores to be current Family Dollar locations.