A firmer Brazilian currency discourages producer selling in the top grower by reducing local-currency returns on dollar-traded commodities such as coffee. Drier weather in Brazil also supported prices, a US trader said. "Light showers will favour the southwest at the beginning of the period, but the majority of the time frame will be dry," weather service Radiant Solutions said in a note.
Technical buying also boosted prices, said Jack Scoville, vice president of Price Futures Group. March robusta coffee settled up $26, or 1.7 percent, at $1,556 per tonne, earlier hitting $1,558, near a one-month high.
March white sugar settled down $4.6, or 1.40 percent, at $324.20 per tonne after touching its weakest since early October at $323.60.
March raw sugar settled down 0.24 cent, or 2 percent, at 11.69 cents per lb at a three-month low.
"The main sellers seem to have been funds and speculators, which is hardly surprising given the current macro environment," said Nick Penney, senior trader at Sucden Financial.
The market continued to follow declining energy prices, which diminish the competitiveness of ethanol in top-grower Brazil, bolstering concerns that mills could switch more production from the biofuel back to sugar.
Markets also focused on ample global sugar stocks, with India poised to export a sizeable chunk of its surplus production to the world market in coming months.
However, "It's beginning to run into some buying interest," said one European dealer. "So I think we'll see the (decline) slow down."
March London cocoa settled down 3 pounds, or 0.2 percent, at 1,760 pounds per tonne, just below this week's 5-1/2-month peak of 1,769 pounds. Earlier in the session, the contract hit 1,773 pounds, its highest since July.
March New York cocoa settled up $6, or 0.3 percent, at $2,400 per tonne.
Hot and dry weather in top-grower Ivory Coast has supported prices, said Scoville. "If the dry weather continues, we might have more to the upside."
Radiant Solutions said "precipitation is expected to remain minimal" for the remainder of the week.