COLOMBIA HELPFUL BUT COFFEE QUOTAS UNCERTAIN--U.S. A U.S. government trade official responsible for coffee policy said prospects for an accord on coffee quotas are still uncertain despite recent Colombian efforts to bridge differences between producers and consumers. Jon Rosenbaum, an assistant U.S. trade representative just back from trade talks in Colombia, said most producing countries now accept some sort of standardized criteria must be agreed to reintroduce coffee quotas. "There is one country which evidently still does not," Rosenbaum said in an obvious reference to Brazil, which has been negative recently on a reintroduction of quotas. Rosenbaum said because of the stance of Brazil the outlook for an agreement to reintroduce coffee quotas at the September International Coffee Organization meeting is hard to predict. He said that during the visit to Bogota he held technical discussions with Colombian officials. While he did not meet with Jorge Cardenas, head of the Colombian coffee producers federation, who was in Europe, Cardenas left a "positive letter," Rosenbaum said. The Cardenas letter responded to a U.S. letter last month which praised Colombia for trying to find a compromise formula for the reintroduction of quotas, but outlined several concerns with the technical details of the Colombian plan. Rosenbaum could not be reached later in the day for comment on a new formula for calculating ICO quotas agreed to by European coffee roasters and traders. Dutch coffee trade association chairman Frits van Horick said in Amsterdam the new formula is based on six year moving averages and would give Brazil an unchanged export quota for the remaining to years of the current coffee agreement. The U.S. has said it will not agree to any coffee quotas unless "objective criteria" which reflect recent changes in the coffee market are used to set export limits.