Dealers said a slightly stronger dollar and a decline in crude oil prices weighed on prices. But the market was underpinned by the prospect of index fund buying starting on Monday as funds rebalance after sugar's poor performance in 2017.
Dealers said the market would keep a close watch on CFTC data to be issued later on Friday to see if speculators had further trimmed a net short position. March white sugar was down $1.10, or 0.3 percent, at $397.60 a tonne.
March arabica coffee was off 0.55 cents, or 0.4 percent, at $1.29 per lb, extending its retreat from a 2-1/2 month high of $1.3135 set on Wednesday. Dealers said the recent run-up had been largely driven by short covering and there appeared to be little interest in taking fresh long positions at current levels.
"The trading volumes have remained thin in recent sessions but have favoured the downside suggesting lack of appetite for current prices," said Sucden Financial technical analyst Geordie Wilkes in a market note. Global coffee exports fell 9.2 percent in November from a year earlier to 9.02 million 60-kg bags, data from the International Coffee Organization (ICO) showed on Friday.
March robusta coffee rose $1, or 0.1 percent, to $1,729 a tonne. March London cocoa was down 3 pounds, or 0.2 percent, at 1,364 pounds a tonne.
The front month had fallen to a three-week low of 1,322 pounds on Thursday before rebounding in late trade. * Dealers said the current strong flow of cocoa to ports in Ivory Coast was keeping the market on the defensive although it was seeing sporadic short covering rallies. March New York cocoa fell by $8, or 0.4 percent, to $1,897 a tonne.