Sealed Air Corp. saw its share price tumble Thursday, down over 15% to $13.23 a share, a 52-week low. The move made it the biggest decliner on the S&P 500 . The Elmwood Park, N.J.-based packaging company released earnings before the open reporting 20 cents earnings per share for the second-quarter, down from 40 cents a share compared with a year ago, and also cut their earnings forecast. Share prices have declined in 2012, down almost 22% since January and down over 34% in the last 12 months. The stock is currently trading at $13.61 a share.

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