Brazil, the world's largest coffee grower, yesterday said it will continue to export all the coffee it can until prices fall and warned the nation's producers against withholding stocks.

In Rio de Janeiro, retail coffee prices rose by 5.1 to 6.8 per cent, bringing ground coffee to $1.63 a pound in package form. Brazil is the second largest consumer of coffee after the United States, which drinks 42.2 per cent of the world's traded coffee.

In Amsterdam, a spokesman for J. Duyvis En Zoon, an overseas associate member of the London Coffee Market, said record high coffee prices had forced the firm to suspend activity because it was unable to meet its "obligations for supply of coffees according to sales contracts made earlier." He said he hoped the firm would resume business when heated trading on the London market stabilizes.

But coffee broke through the $6,800-a-ton mark and hit $6,834 yesterday on the London market when contracts for delivery in November soared by more than $221. Dealers attributed the rise to higher prices in New York, Brazil's increase in its minimum export price Monday and the state of emergency declared in El Salvador.