More on Arch Coal's (ACI) Q4 results: Sales price declined $0.67/ton Q/Q, in part due to lower prices on export sales. Cash costs increased $0.66/ton, reflecting anticipated higher maintenance expense. Expects sales of 133M-144M tons for full-year 2013, with cash costs per ton similar to 2012 levels. Expects stronger performance in H2 than H1. Shares -4.4% premarket.