PotashCorp BHP Billiton

FILE- This 2007 file photo, shows the cutting face of a potash borer in a deep shaft at the Rocanville potash mine, owed by the PotashCorp of Saskatchewan, in Rocanville, Sask. The fertilizer producer said Tuesday, Aug. 17, 2010, it has rejected an unsolicited takeover bid from BHP Billiton Ltd. worth about $38.49 billion as "grossly inadequate." (AP Photo/The Canadian Press, Troy Fleece, File)