SOFTS-US cocoa falls from 30-year peak, arabica sinks

* Strong dollar pressures U.S. cocoa, coffee

* Robusta coffee dealers see origin selling pressure

* Weak sterling boosts London cocoa futures (Recasts with markets closing levels, adds U.S. comment, and NEW YORK dateline/byline)

NEW YORK/LONDON, Oct 23 - Coffee futures tumbled to close down around 5 percent on Friday, while U.S. cocoa reversed off a 30-year high with pressure coming from the strong dollar.

Sugar was little mixed as the markets consolidated, supported by worries over the impact of heavy rains in top grower Brazil on yields, while London cocoa, which is traded in pounds, felt a boost from the weak currency.

Arabica coffee fell sharply in heavy volume, falling on a wave of automatic sell orders.

"There doesn't seem to be much in the way of fundamental news to me. Once it got below $1.40, it was (sell) stop city," said Jack Scoville, analyst for brokers The Price Futures Group in Chicago.

ICE benchmark December arabica coffee futures closed down 6.50 cents or 4.5 percent, at $1.3715 per lb.

"Robustas were the first to crack. There was possibly some origin, and fund, selling (in London) provoking the sell-off in New York," said one London-based coffee dealer.

London November coffee ended $74 lower at $1,363 a tonne.

In U.S. cocoa, the market breached near-term resistance at $3,400 per tonne, basis December, and hit the highest level for the spot contract since June 1979 at $3,412. The market then turned lower on pressure from the weak pound against the dollar and as some market participants grabbed profits.

U.S. cocoa closed down $27 at $3,365 per tonne.

"Generally, you've got very positive chart trends. You've got worries about production in the coming year," Scoville said.

March cocoa in London ended 16 pounds higher at 2,207 pounds a tonne, after hitting 2,221 pounds, a 24-1/2-year high on a continuation second-month basis.

The market was underpinned by improving demand as the global economy recovers and concerns over tight supplies in West African producers, dealers said.

A drop in the pound after news that Britain's economy contracted unexpectedly in the third quarter of this year supported sterling-denominated London futures.

Raw sugar futures rose in thin and choppy trading, underpinned by concerns over tight supplies, particularly due to heavy rainfall in top producer Brazil.

"I think sugar is in a consolidation mode," said Sterling Smith, an analyst for brokers Country Hedging Inc. in Minnesota.

The market needs fresh news to determine its next move, Smith said.

Pierre Sebag of consultancy Sugar K Ltd said he believed raw sugar futures were set to consolidate below recent 28-1/2-year highs, with renewed cash offtake needed to push the market up.

"I think the immediate outlook for prices is sideways, with the key focus on the rains in Brazil," he said.

Raw sugar futures more than doubled this year due to the combined impact of a poor Indian crop which led to hefty imports to the world's top consuming country, and the rainfall in Brazil which delayed supplies and threatened yields.

ICE March raw sugar inched up 0.04 cent to close at 23.12 cents a lb, while Liffe December white sugar settled $3.60 lower at $583.50 per tonne.