"Currencies are a big factor this week. The way they have strengthened recently means traders simply cannot afford to sell," one Singapore dealer said.

A strengthening of Thailand's baht and particularly Indonesia's rupiah -- quoted at around 9,000 to the US dollar on Thursday compared with about 10,800 a week ago -- was playing havoc with traders' positions.Having bought coffee from farmers when the rupiah was at around 13,000 to the dollar, selling now would guarantee losses.

"At least it is the end of the season in Indonesia and there is not much left to sell," another trader said.

Indonesian Grade 4, 80 defects coffee was trading at $1,430/450 per tonne fob Lampung on Thursday. Meanwhile, concerns that Asia's coffee crop could be harmed by the La Nina weather phenomenon, which follows hot on the heels of El Nino-inspired drought, werealso making traders jittery.

"Everybody in the agriculture business in this region is concerned about the impact of La Nina because they saw the huge impact of El Nino last year," a senior Asian coffee trader said.

El Nino is caused by warmer-than-normal Pacific Ocean temperatures, causing drought in Asia. La Nina is caused by colder-than-normal Pacific temperatures and usually brings wet weather in its wake.

On the buying side, the strengthening of the Japanese yen had seen some sniffing around in the market from Tokyo-based bidders, although coffee trade had remained fairly lacklustre.

"I haven't noticed anybody asking for anything major this week. The standard buyers are in the market as always, but that's all," a broker with a European trading house said.

The market was also subdued by tightening supply-side factors caused by the overlap between the end of Indonesia's harvest season and the anticipated start of the Vietnamese harvest.

Early signs from Vietnam were mixed, dealers said. Somewere expecting a reasonably healthy yield, while others held more pessimistic views.

One Bangkok-based trader said initial picks showed the coffee beans to be smaller than last year, which could have implications for a lower yield.

Another trader said early beans were always smaller and improved towards November's harvest peak.

Vietnamese coffee prices were largely unchanged from a week ago, hovering around $1,430/450 for Grade 2, 5.0 percent black and broken robusta.The uncertainty served to keep Asian coffee prices broadly similar to the previous week: "The graph of the robusta market goes from 1,150-1,650 and that's the area it's trading in at the moment," one Singapore-based analyst said. However with prices rising in London, differentials were widening.

Some traders said they had seen a discount of as much as $200 per tonne on Vietnamese robusta. Some upside potential was seen given the volatility in global equity and currency markets and falling bond yields. "I think there could be a technicalpush. People are not making money on the stock market, they're not making money on foreign exchange or on futures, so the fund managers will say 'put your money in commodities which are at a nice low price'. That could push prices up," the Singapore analyst said.