Mining giant BHP's credit rating cut on low commodity prices: S&P

Mining giant BHP Billiton's credit rating was cut by Standard & Poor's on Tuesday as it is battered by plunging global commodity prices, with the agency warning of further downgrades. The move will put pressure on chief executive Andrew Mackenzie, who has pledged to keep the firm's A-grade rating in the face of price headwinds. "In this environment, we are also committed to protecting our strong balance sheet so we have the financial flexibility to manage further volatility and take advantag