Japan trading houses quadruple profit in 2 years

Buffett-backed Japan trading houses quadruple profit in 2 years

TOKYO -- Five of the biggest winners this earnings season have diversified global operations that link Japan to sources of energy and food as well as overseas markets.
 
They also have a shareholder in common: Warren Buffett's Berkshire Hathaway.
 
Trading houses Mitsubishi Corp., Itochu, Sumitomo Corp., Mitsui & Co. and Marubeni are riding high. But can they sustain their gains as commodity prices fall?