London white sugar futures closed lower on fund selling late in the session on Friday, reversing earlier gains on trade buying, traders said.
December settled down $2.2 at $235.3 a tonne in volume of 3,448 lots, after trading in a $235-240 range.
March ended down $2.3 at $250.3 in volume of 1,065 lots.
"Funds have been selling in London after trade buying earlier in the day," one trader said.
"Today volumes have been light, with trade and medium speculator buying this afternoon," one trader said before the market turned negative on fund sales late in the session.
Another trader said much of Friday morning's relatively light activity had been centred on trade buying of December.
Some analysts said sugar's recent bull run was bloodied.
"The bulls are losing heart, frustrated by the way the market has been trading recently - stuck in a range for the last few months with a slow erosion of fund longs," said Paris-based broker Jonathan Kingsman in an editorial.
The white sugar futures market has already factored in a forecast by a prominent industry group for another record centre-south Brazilian sugarcane harvest, traders said.