HANOI, May 11 - Coffee export markets were quiet this week as Indonesia is on holiday while premiums in Vietnam edged lower on weak demand, traders said on Thursday.

The 5 percent black and broken grade 2 robusta in Vietnam, the world's largest grower of robusta beans, was quoted at a premium of $10-$20 per tonne to London's ICE July contract, easing from last week's $20-$30 premiums.

"The market is very slow. Foreigners are not buying ... they might have bought enough beans already," said Le Duc Huy, Deputy general director of Simexco, a leading exporter in Daklak, the country's largest coffee growing province.

Coffee traded locally at 44,000 dong ($1.94) to 44,500 dong ($1.96) per kg, down slightly from 44,800-45,000 dong a week earlier, traders said, adding that farmers are still eyeing a price hike before releasing more beans.

"Local prices used to be 46,000-47,000 dong just recently, so farmers feel that selling at this price is just ugly, they are not ready to live with low prices yet," said Nguyen Quang Binh, head of the coffee section at Visimex Joint Stock Company.

"They are waiting for some price changes," he added.

Vietnam's coffee exports in April were revised down to 135,000 tonnes (2.25 million 60-kg bags) from an earlier forecast of 150,000 tonnes. April exports of the beans declined 19.8 percent from the same month last year.

Indonesian markets are closed on Thursday for a public holiday.

($1 = 22,722 dong)