Check out which companies are making headlines before the bell:
PetSmart—The pet supplies retailer agreed to be bought for about $8.25 billion, or $83 per share. The buyer is a group led by buyout firm BC Partners.
Bob Evans Farms—Chief Executive Steve Davis resigned "by mutual agreement," with the restaurant operator saying board members had concluded that the company would benefit from new leadership.
Exxon Mobil—BMO Capital Markets upgraded the oil giant's stock to "market perform" from "underperform," citing Exxon's defense posture despite BMO's view that the stock is expensive compared to its peers.
Keurig Green Mountain—The coffee company is moving most of its Vermont-based coffee buying operation to Switzerland, in what the company calls a move to position it as a "global beverage player."
Ford—Deutsche Bank cut its rating on the automaker's stock to "hold" from "buy," with the auto sector now in its sixth year of recovery and Ford shares within seven percent of the firm's 12-month target.
Twitter—JMP began coverage of Twitter with an "outperform" rating, citing extreme brand awareness and the idea that Twitter is THE go-to place for news and information among its 284 million active users.
United Parcel Service—Deutsche Bank downgraded UPS to "hold" from "buy," with the risk/reward profile now more balanced after a 9.5 percent jump in the stock since the most recent UPS earnings report.
Emerson Electric—The company is selling its power transmission business to Regal Beloit for about $1.4 billion in cash. Regal Beloit is a maker of various power products like electric motors and generators.
Burlington Stores—The retailer has announced an eight million share secondary offering, with the shares coming from stockholders. Burlington will not sell any of its own shares nor receive any proceeds from the offering.
Juniper Networks—The networking products maker may add new directors to its board, following talks with activist investor Elliott Management. Dow Jones reports the two sides could come to an agreement that would avoid a proxy fight. Elliott owns about nine percent of Juniper's shares.
American Airlines Group, Electronic Arts, Lam Research—The three stocks are being added to the Nasdaq 100 index in the annual re-ranking, with Expedia, F5 Networks, and Maxim Integrated Products being removed. The changes will take place before the market opens next Monday, December 22.
Sony—Sony is said to have demanded several news organizations—including The New York Times, The Hollywood Reporter, and Variety—to stop reporting information contained in documents stolen by hackers from Sony's computer systems.
General Electric—The company could get $1.2 billion for the Australian operations of its GE Money unit, according to a Bloomberg report, with several bids having been submitted for that business.