Farmers in the Central Highlands, Vietnam's largest coffee-growing area, sold coffee at 33,000-33,500 dong ($1.42-$1.45) per kg, compared with 33,000-33,200 dong a week earlier.

"Domestic prices have gone up as anticipated, partly because of the fears over virus, and because of low stocks," one of the traders based in the coffee belt said.

The 2019/20 crop season will end in September, with traders saying coffee trees were growing well and new beans would arrive in November.

Traders in Vietnam offered 5% black and broken grade 2 robusta at a $70 premium per tonne to the November contract. The premium was $130 per tonne to the September contract.

November robusta coffee settled down $24, or 2%, at $1,362 per tonne on Wednesday.

In the Indonesian province of Lampung, Sumatran robusta beans were offered at $180-$190 premiums to the September contract, down from a $240 premium last week.

"It's because supply of coffee beans is abundant this week as the harvest is reaching its peak," said one trader in Lampung, adding that the harvest period was expected to last until around end-September.

Indonesia exported 15,912.3 tonnes of robusta coffee beans in July from Lampung province, local trade office data showed.

($1 = 23,173 dong)

By Phuong Nguyen and Mas Alina Arifin