Indonesia coffee traded at highest premium since Nov '09
    * Sumatran beans sold at $75 to $100 premiums
   * Supply worries linger
(Adds details, quotes) 
   SINGAPORE, May 23 (Reuters) - Indonesian coffee changed hands at their highest premiums since November 2009 because of a supply squeeze in the world's second-largest robusta producer after Vietnam, dealers said on Monday. 
   Sumatran robusta beans were traded at premiums of up to $100 to London's July contract <LRCN1>, but there were no details of volume or buyers. Robusta was offered at premiums of up to $80 last week.  
  

   Exporters in Indonesia's main growing island of Sumatra are struggling to get beans after persistent rains caused a shift in harvesting time, which eventually damaged coffee cherries.  
   Harvests in Sumatra usually begin in March or April, but yields are down as farmers have been picking cherries since January after persistent rains caused the flowering season to begin earlier in some districts.   
   "Global robusta coffee prices may challenge a recent three-year peak as continued heavy rains in Indonesia cause severe damage to unripe cherries and threaten the harvest, leading exporters to cancel shipments," said Herve Touraine, a dealer at  SW Commodities. 
   "The Indonesian differentials are reacting to the situation, some EK1 were traded with $100 premium over the London Liffe probably on physical short covering rather than desperate needs for robusta," said Touraine, referring to the Indonesian grade. 
   A dealer in Bandar Lampung, the provincial capital of Lampung on Sumatra, said robusta beans were traded at premiums of between $75 to $100 a tonne against July contract, which fell $6 to settle at $2,543 a tonne on Friday.   
   The International Coffee Organization said Vietnam's 2010/2011 coffee output rose 5.5 percent from the previous crop to 18.5 million bags, while production in Indonesia would fall 25.3 percent to 8.5 million bags due to rainy weather.    
   Indonesian exporters have cancelled the shipment of at least 3,000 tonnes of robusta beans for April and May deliveries due to difficulties in getting supply following erratic harvests. 

 (Reporting by Lewa Pardomuan; Editing by Himani Sarkar)     
   
Monday, 23 May 2011 16:03:12RTRS