A trader works on the floor of the New York Stock Exchange.

AstraZeneca – Pfizer continues to press its case for its takeover bid , issuing a new statement promising that jobs would remain in the U.K. Pfizer also posted a video on its web site saying large transactions such as this one do not disrupt drug research, and CEO Ian Read is preparing to defend his offer before British lawmakers tomorrow.

Pinnacle Foods – Hillshire Brands is acquiring Pinnacle in a $6.6 billion cash and stock deal , worth $36.02 per share. That represents an 18 percent premium over Friday's close for Pinnacle shareholders.

Check out which companies are making headlines before the bell:

Pandora–MKM upgraded the online radio service's shares to "buy" from "neutral", both on upbeat ad prospects and that fact that, in the firm's view, Apple is executing poorly with its iTunes Radio product.

Apple– Merrill Lynch analyst Scott Craig said Apple's acquisition of Beats for $3.2 billion is "expensive" and "out of character", while maintaining a "neutral" rating on the stock.

21st Century Fox–The company is in talks with fellow Rupert Murdoch holding British Sky Broadcasting about buying BSkyB's pay-TV properties in Germany and Italy.

Credit Suisse–Credit Suisse and BNP Paribas have reportedly asked the U.S. to allow their subsidiaries rather than the parent companies to plead guilty in probes involving helping wealthy Americans evade taxes. That's according to New York Times, which said prosecutors are not inclined to grant those requests.

General Motors–The embattled auto giant ranked as the worst automaker in a new survey of automotive suppliers.

T-Mobile U.S., Sprint —Deutsche Telekom is seeking a breakup fee of more than $1 billion if regulators do not approve a merger of the company's T-Mobile U.S. unit with Sprint, according the Wall Street Journal. The paper said the breakup fee is a key point as the two sides try to finalize a deal.

Twitter–SunTrust Robinson Humphrey upgraded Twitter to "buy" from "neutral."

—By CNBC's Peter Schacknow

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