May 1 (Reuters) - The Reserve Bank of Australia's (RBA) index of commodity prices dipped 1.6 percent in April, from March, due mainly to falls in coal, gold, oil and aluminium.
In March, the index had risen 0.5 percent in special drawing rights (SDR) terms.
The index reading of 137.8 in April was 4.2 percent lower than the same month last year. Much of that fall was due to lower prices for coal, iron ore and wheat, the RBA said.
In Australian dollar terms, the index rose 0.4 percent in April, leaving it down 5.2 percent for the year.