Check out which companies are making headlines before the bell:
Baker Hughes—The oilfield services company will be bought by rival Halliburton for $34.6 billion in cash and stock. Baker Hughes shareholders will receive 1.12 Halliburton shares plus $19 for each share they now hold, valuing the deal at $78.62 per share.
Procter & Gamble—Canaccord downgraded the consumer products giant's shares to "hold" from "buy" on a valuation basis, saying the current price captures all the improvements made by P&G.
Marriott—UBS downgraded the hotel operator's stock to "neutral" from "buy," following a 58 percent year-to-date run-up in the stock. UBS said it still likes the Marriott story, but there are signs of slowdown in the current growth cycle. The firm also downgraded Starwood to "neutral" from "buy" for similar reasons.
Tyson Foods—The poultry and meat producer reported adjusted fiscal fourth quarter profit of 87 cents per share, 11 cents above estimates, with revenue essentially in line. Tyson said the fourth quarter concluded a second consecutive year of record sales and earnings, and that its integration of Hillshire Brands is going well.
Allstate—KBW downgraded the insurer's stock to "market perform" from "outperform" as the shares come close to the firm's target price. KBW said its outlook for Allstate remains unchanged and it would revisit its opinion on any pullback in the stock's price.
General Motors—GM vehicle owners will have an extra month to file claims related to faulty ignition switches, after program administrator Kenneth Feinberg announced that the deadline has been extended to January 31, 2015.
Facebook—The company is said to be developing a workplace version of its social network, according to the Financial Times. The new website would let users keep separate work profiles.
Bristol-Myers Squibb—The pharma company's treatment for advanced melanoma showed promising results, including a much higher survival rate, in a late-stage study.
Microchip Technology—The chip maker issued a statement saying it had approached CSR about a possible business combination, but that the talks have been terminated and that it does not intend to make an offer.