* Platts' Jonathan Kingsman sees bearish sugar market tone
* Rabobank analysts peg 13/14 sugar surplus at 2.5 mln T
* Brazil's Conab forecasts '14 coffee output falling 1.6 pct
* Origin selling pressure just above current cocoa prices
(Updates with closing sugar, coffee prices; adds Rabobank forecast in paragraph 6)
NEW YORK/LONDON, Jan 9 (Reuters) - ICE raw sugar futures prices on ICE dropped to a 3-1/2 year low on Thursday in their biggest two-day rout since September, extending a long-term downtrend on chart-based selling, currency pressure, and excess supplies.
Arabica coffee on ICE Futures U.S. fell as dealers assessed the week's volatile trade and lowered output expectations for top grower Brazil, while cocoa futures slipped.
March raw sugar futures on ICE finished down 0.26 cent, or 1.7 percent, at 15.48 cents a lb, after having set a 3-1/2-year low for the front month of 15.41 cents a lb and tumbling 2 percent on Wednesday.
"The market is already voting with its feet, making new contract lows and the lowest prices since 2010. Spreads are widening," said Jonathan Kingsman, head of agriculture at data provider Platts. "Everything looks very bearish."
The sugar market has started 2014 with a bearish tone after falling for three straight years.
Rabobank analysts said in a report that their latest projections point to another year of building stocks and a surplus of 2.5 million tonnes in the 2013/14 crop year, a fourth consecutive year of global production outpacing supplies.
Dealers said sugar prices might drift down further, with India's government likely to agree on measures to promote exports to an already oversupplied market.
Trading continued to be heavy following Tuesday's furious activity, when futures volumes reached 152,773 lots and the highest levels since October, according to exchange data.
"Very little demand is showing up ... there is talk of origin selling. That is a danger," said Michael McDougall, a senior vice-president for broker Newedge USA.
March white sugar on Liffe lost $6.70, or 1.5 percent, to finish at $425.60 per tonne.
ICE March arabica coffee futures fell 1.55 cents, or 1.3 percent, to settle at $1.1935 per pound, continuing the week's volatile trade on a wide range of 2014/15 crop forecasts for Brazil.
The Brazilian government agency Conab on Thursday projected 2014 output down 1.6 percent at 48.34 million 60-kg bags.
The forecast failed to send prices to fresh highs as dealers assessed a week of conflicting industry forecasts.
"We are a little overheated here, and the Conab number wasn't a big surprise," said Sterling Smith, a futures specialist with Citigroup in Chicago.
Dealers said the market had absorbed a wave of producer selling and investor profit-taking that followed a peak at $1.2260 on Tuesday, a high for the spot contract since Aug. 15
Liffe March robusta coffee settled up $15, or 0.9 percent, at $1,727 a tonne.
ICE March cocoa closed down $16, or 0.6 percent, at $2,684 a tonne after mixed trading throughout the day.
Liffe May cocoa slipped 8 pounds, or 0.5 percent, to 1,708 pounds a tonne.
Prices were weighed by signs production in top grower Ivory Coast looked set to exceed initial expectations and supplies are readily moving in West Africa, the world's top growing region.
Ghana's main crop purchases have so far risen 37 percent year-over-year, according to data obtained by Reuters.
Even so, dealers said cocoa was underpinned by expectations that fourth-quarter grind data for Europe and North America, due to be issued next week, is likely to show year-on-year increases of around 5 percent.
(Editing by Sophie Hares and Marguerita Choy)