A supertanker-load of one of the key North Sea crudes has recently sold in Asia at a very low price – below the spot North Sea price and below the price of a Middle Eastern grade – in a sign that Asian demand for crude continues to be softer than anticipated. A cargo of 2 million barrels of Forties, one of the grades underpinning Dated Brent, was sold last week to South Korean refiner GS Caltex Corporation at a price that was $3.50-$4.00 a barrel below the North Sea spot price, traders with knowledge of the deal told Bloomberg on…