MUSWELLBROOK, AUSTRALIA - FEBRUARY 15: Coal trucks pass each other at BHP Billiton's Mt Arthur coal mine February 15, 2006 in Muswellbrook, Australia. BHP today posted the biggest interim profit in Australian corporate history. The world's biggest mining company announced a half-year after tax profit of $5.9 billion AUD ($4.37 billion USD) a rise of almost 48 per cent from last year. (Photo by Ian Waldie/Getty Images)