(Updates prices; adds comment, exchange data, NEW YORK dateline) NEW YORK/LONDON, Sept 28 (Reuters) - Coffee futures on ICE fell to three-week lows on Thursday, weighed down by fresh speculative selling against a backdrop of crop-friendly weather forecasts in top grower Brazil.
* December arabica coffee settled down 0.85 cent, or 0.7 percent, at $1.285 per lb, after dropping to $1.275, its weakest since Sept. 7.
* "The funds are getting short again as we speak," said one dealer. "The reality is that if there's no weather problem, Brazil is going to have a very good crop."
* While producers in Brazil are still reluctant to sell at current levels, and they await much-needed rain, further
weakening in the Brazilian real could draw more coffee
into the market, dealers said.
* November robusta coffee settled down $1, or 0.05 percent, at $1,949 per tonne, after falling to the lowest since Sept. 7 at $1,921.
* December New York cocoa settled down $35, or 1.7 percent, at $1,980 per tonne, as the market corrected from the previous session's rally.
* Uncertainty about how many shipments of Ecuadorian cocoa containing itch grass have been rejected by the United States lifted December's premium over March <CCZ7-H8> to a $7 premium on Wednesday, up sharply from a $13 discount three weeks prior. It narrowed to a $1 premium on Thursday.
* "There's a certain amount of concern in terms of how much impact that's going to have," said one dealer. "And it coincides with a very sizeable investor spec short that's been rolling its position (forward)."
* Exchange data showed certified stocks from Ecuador are down roughly 80 percent from September 2016.
* December London cocoa settled down 22 pounds, or 1.5 percent, at 1,476 pounds per tonne.
* March raw sugar settled up 0.12 cent, or 0.9 percent, at 13.95 cents per lb.
* Short-covering lifted prices above Monday's three-month lows as traders prepared for the end of the month and the end of the third quarter, traders said.
* "Most of the technical indicators remain on the 'sell' side today although the overall picture may be slightly clouded to anticipate tomorrow's expiry and the COT report," said Agrilion Commodity Advisers in a note.
* The October contract , which expires on Friday, closed up 1.1 percent at 13.23 cents. Open interest fell by 13,760 lots to 27,515 lots as of Wednesday.
* December white sugar settled up $2.50, or 0.7 percent, at $358.70 per tonne.
(Reporting by Marcy Nicholson in New York and Ana Ionova in London; Editing by David Clarke and James Dalgleish)