Premarket Movers: Office Depot drops on outlook

The office supply retailer blamed a slowing economy and said it expects the economic environment to be "difficult" in the second half. Shares fell 14.6 percent to $8.89 in action before the bell.

IndyMac Bancorp Inc. said it has stopped accepting new loan submissions in its retail and wholesale forward mortgage lending channels and will cut 3,800 jobs, or more than half its staff. Shares of the Pasadena, Calif., company fell 35 percent to 44 cents in premarket action.

Shares of Energy Conversion Devices Inc. jumped in premarket trading Tuesday after the solar energy product maker said it will supply solar cell laminates to General Motors Corp. for the world's largest rooftop power generation system.

The stock added 5.2 percent to $68.75, while GM shares added 9 cents to $10.35.

Separately, GM said Tuesday its auto sales grew in China in the first half.

Shares of UAL Corp., parent of United Airlines, rose 5 percent to $4.40 after announcing it would cut 150 jobs at Denver International Airport. By law, employers with a certain number of workers in Colorado are required to notify the state of large job cuts.

Novartis AG moved closer to completing its $38 billion takeover of U.S. eye-care company Alcon Inc. Shares of the Swiss pharmaceuticals company jumped 2.7 percent to $57.50 after it said it completed the first stage of the deal.

Shares of Medivation Inc. rose 4.1 percent to $12.55 after the biotechnology company said its drug candidate Dimebon was shown to be safe and improve the mental function of Huntington's disease patients in a midstage study.