U.S. dollar up as China devalues yuan

By Wayne Cole SYDNEY (Reuters) - The U.S. dollar lurched higher on Tuesday as China allowed its yuan to fall to levels last seen in 2012, a move that could provide a competitive boost to exports from the world's second largest economy. China's central bank set the mid point for its currency at 6.2298 per dollar, down from Monday's fix of 6.1162, and said it was aiming for a depreciation of 2 percent. Markets reacted by selling the Australian dollar, often used as a liquid proxy fo