Farmers in the Central Highlands, Vietnam’s largest coffee growing area, sold coffee COFVN-DAK at 29,000-29,800 dong ($1.24-$1.27) per kg on Thursday, down from 30,300-31,000 dong last week.

"Fresh concerns about the trade war between the United States and China and the strong sales from Brazil have pushed down global robusta prices," a trader based in the central Highlands said.

July robusta coffee settled down $5, or 0.4 percent, at $1,290 per tonne, after earlier plunging to $1,267, the lowest since March 2010.

Traders in Vietnam offered 5 percent black and broken grade 2 robusta COFVN-G25-SAI at a $45 per tonne discount to the July contract, flat from last week.

Customs data released on Thursday showed Vietnam’s coffee exports in April falling 16.7 percent from March to 143,296 tonnes, slightly higher than a government forecast of 140,000 tonnes.

Meanwhile, in Indonesia, premiums for the grade 4 defect 80 robusta COFID-G4-USD rose to $200-$240 to the July contract on Thursday from $170 a week ago, according to a trader based in Lampung.

"The premium widened further to compensate for the decline in benchmark contract prices," the trader said.

Supplies in Indonesia are increasing as the harvest in the southern part of Sumatra is picking up pace, he added.