The Reserve Bank of Australia's index of commodity prices in special drawing rights (SDR) terms fell by 3.5 per cent in May, preliminary estimates from the central bank show.
This follows a revised fall of 12.8 per cent in April.
The largest contributors to the fall in May were decreases in the estimated prices of coking coal, iron ore and steaming coal.
The prices of gold, nickel, sugar and wheat rose.
In Australian dollar terms, the index fell by 8.21 per cent in May, following a revised fall of 18.1 per cent in April.
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