Indonesia will keep its export tax for crude palm oil at zero for a third month in June, the country's trade ministry said in a statement on Friday.

The country's cocoa export tax will also be kept at 5% in June.

Indonesia imposes its progressive export tax on crude palm oil based on the government's reference price. The tax kicks in when the price goes above $750 a tonne.

The reference price in June was $568.94 a tonne, the ministry said, down from May's $635.15

Based on existing regulation, the decline in reference price should mean crude palm oil exporters will not have to pay an additional levy.

Indonesia, the world's biggest producer and exporter of palm oil, collects an additional export levy when the reference price is above $570.

Finance Minister Sri Mulyani Indrawati's said earlier this month that the government planned to raise palm export levies by $5 to support the country's biodiesel programme.

(Reporting by Bernadette Christina Munthe; Writing by Gayatri Suroyo. Editing by Jane Merriman)