Domestic coffee prices in Vietnam fell this week after the International Coffee Organisation raised global surplus forecast, while Indonesian premium expanded further.

Farmers in Vietnam’s Central Highlands sold coffee at 30,900-31,800 dong ($1.33-$1.37) per kg on Thursday, down from 31,600-32,500 dong last week.

“Domestic prices fell further after the International Coffee Organisation last week raised its forecast for global coffee production,” a trader based in Ho Chi Minh City said.

The ICO last week raised its estimate for robusta production in 2018/19 to 64.37 million bags from 63.50 million bags.

Another trader based in Ho Chi Minh City said prices in Vietnam also fell after customs data showed that actual coffee shipments in March were higher than the government’s estimate.

Customs data released on Wednesday showed Vietnam exported 172,080 tonnes of coffee in March, up 49.5 percent from February and higher than a government estimate of 160,000 tonnes.

Traders in Vietnam offered 5 percent black and broken grade 2 robusta at a $60 per tonne discount to the July contract, compared with $75 discount last week.

May robusta coffee settled up $4, or 0.3 percent, at $1,424 per tonne on Wednesday.

In Indonesia, premium to the May contract expanded further this week but trading activity remained muted, a trader in Bandar Lampung said.

Premium for the grade 4 defect 80 robusta rose to $150 to the May contract on Thursday from $100-$110 a week ago, the trader said.

Another trader there said premiums for the robusta were unchanged at $100-$110 to the May contract.