Vietnam robusta sellers tracked gains in London, pushing prices higher while speculators held back their stock on hopes of further price rises, traders said on Tuesday.
Traders said the harvest of the 2003/2004 crop in the Central Highlands coffee belt had been completed as farmers prepare for the Lunar New Year Tet festival this week.
Export offers of five percent black and broken beans firmed to around $700 per tonne, FOB basis, from between $670 and $690 last week and $650 to $660 two weeks ago.
On Monday, the benchmark London March closed $28 higher at $822 a tonne while May gained $28 to close at $833.
Domestic prices in the key coffee-growing province of Daklak tracked the rise, edging up to 9,300 to 9,400 dong (59.5 to 60 cents) per kg on Tuesday from 9,200 dong last Friday.
Farmers have been selling beans to middlemen for cash before Tet, but the middlemen have been reluctant to sell in quantity to exporters on hopes of more price gains, traders said.
Discounts to the March contract widened to $110 a tonne, from $100 to $105 a week ago.
Vietnam's coffee crop year lasts runs from October to September while the four-month harvest ends in late January.
Last year traders estimated the 2003/2004 crop would rise nearly 30 percent to 710,000 tonnes.
Vietnam exports mostly robusta beans, a variety widely used in production of instant coffee.