JAKARTA, May 31 (Reuters) - Indonesia has set its crude palm oil (CPO) reference price for June at $778.82 per metric ton, a Trade Ministry regulation showed on Friday, down from $877.28 in May.

The new reference price would put the export tax for CPO at $18 per ton and levy at $75, down from this month's rates. (Reporting by Bernadette Christina; Editing by Martin Petty)