Australia's commodity price index retreated in June, pulling back 2.2% on a monthly average basis in Special Drawing Rights (SDR) terms after a 1% gain in May, driven by weakness in non-rural and base metals subindices while rural commodities bucked the trend, according to a Wednesday report by the Reserve Bank of Australia.

SDR, an international reserve asset created by the International Monetary Fund, is used by the RBA as a currency-neutral unit of account to measure the index. In Australian dollar terms, the index slipped 0.7% in June.

Despite the June decline, the index has climbed 16.9% over the past year in SDR terms, with gains in gold, coking coal, and rural commodities more than offsetting weakness in liquefied natural gas (LNG) and alumina, while the index is up 8% in Australian dollar terms over the same period, the report added.

A spot price measure of the bulk commodities index showed a monthly decline of 2.4% in SDR terms in June, though it remains 19.7% higher on a year-on-year basis, it added.