As world shares rose, the dollar weakened, and was down 0.3% against a basket of currencies at 89.754 at 1222 GMT.The Australian dollar rose against the U.S. dollar, crossing $0.8 for the first time in three years.The Canadian dollar also hit new 3-year highs against the U.S. dollar, up 0.3% at 1.2481 at 1224 GMT.