* Higher-than-expected Unica data weighs on sugar
* European Q4 cocoa grind may rise by 2 to 3 percent
* Arabica forms double bottom with Monday's 8-week low (Updates prices; adds comment, byline, NEW YORK dateline)
By Marcy Nicholson and David Brough
NEW YORK/LONDON, Jan 12 (Reuters) - Raw sugar on ICE fell for the seventh straight session and hit a two-month low in heavy volume on Tuesday, forming a potentially supportive technical pattern after the release of stronger-than-expected cane data in center-south Brazil.
New York cocoa futures fell to an 8-1/2-month low, hurt by the sharply lower British pound, in their seventh down session out of the past eight.
Arabica coffee futures inched lower on pressure from the strong U.S. dollar, matching Monday's nearly eight-week low but consolidating after the prior session's 3.8 percent tumble.
Sugar turned lower after data from cane group Unica showed a bigger-than-expected 210 percent jump in Brazil's center-south sugar production in the second half of December from a year earlier as mills tried to make up for weeks lost to rain this season.
"The focus now will be prospects for the next harvest in center-south Brazil," said Capital Economics commodities economist Hamish Smith.
March raws settled down 0.1 cent, or 0.7 percent, at 14.05 cents per lb after touching a two-month low at 13.93 cents a lb. This double bottom with the Nov. 9 low formed a potential technical support level.
March whites settled down $2.30, or 0.6 percent, at $412.50 per tonne.
"The ... Unica data stoked worries that supplies from the world's top grower would be higher than previously expected," said Michael McDougall, director of commodities at Societe Generale in New York.
New York cocoa fell, pressured by the weak pound that tumbled to the lowest against the dollar in 5-1/2 years and the general risk-off mood in commodities that has pushed the 19-market Thomson Reuters CoreCommodity Index to a 13-1/2-year low.
Traders said European fourth-quarter grind data due on Friday could help stem the market's slide if it surpasses expectations of a year-on-year rise of 2 percent or 3 percent.
March New York cocoa settled down $42, or 1.5 percent, at $2,860 per tonne in heavy volume, after falling to $2,852, the lowest since April.
"We're seeing strong system fund liquidation coming into the market," one London-based broker said. "No one is brave enough to buy aggressively."
March London cocoa settled down 5 pounds, or 0.2 percent, at 2,063 pounds per tonne after dropping to 2,044 pounds, the lowest since August.
March arabica coffee settled down 0.1 cent, or 0.1 percent, at $1.1435 per lb, while March robusta coffee settled up $4, or 0.3 percent, at $1,448 per tonne. (Additional reporting by Chris Prentice in New York; Editing by Mark Potter, Susan Fenton and Lisa Von Ahn)