"Most of them have now stopped quoting coffee prices as London was down. They were really happy," said a dealer in Vietnam's main coffee producing province of Daklak. London July had peaked at $1,594 a tonne after a two-day rally before falling to $1,538 a tonne at the close of trading. Vietnam's robusta grade two, five per cent black and broken, was quoted at $1,260-1,280 a tonne, FOB Saigon Port, after peaking at $1,350 the previous day. Eight percent black and broken grade was seen $25 under, traders said.

A coffee trader in Ho Chi Minh City said some exporters were seeking to seal deals on fears that London prices would drop further. A state coffee exporter predicted London prices on Friday would drop to $1,500 a tonne or even lower.

"It's time for us to buy beans, not to sell," he said. "But when the price moves down the farmers may holdback as well." Traders said London and New York markets moved quickly in the past two days so that only a few Vietnamese traders had been able to secure good deals.