(Rewrites throughout; updates prices; adds comment, NEW YORK dateline) NEW YORK/LONDON, Feb 27 (Reuters) - Raw sugar futures on ICE tumbled in heavy volume to an eight-month low on Tuesday, on chart-based selling as the market breached key support levels and on expectations for abundant supplies. The move sharply narrowed the March premium over May ahead of the spot contract's expiry on Wednesday.
* May raw sugar settled down 0.56 cent, or 4.2 percent, at 12.87 cents per lb after sinking to an eight-month low for the second position of 12.84 cents.
* Technically driven selling gathered pace as the market broke below the February low of 13.20 cents and then last month's low of 13.17 cents.
* Expectations for a global 2017/18 surplus also weighed on prices and speculators may be beginning to reestablish short positions after scaling them back so far this month, traders said.
* The tumble came ahead of the March contract's expiry on Wednesday and moved its premium over May <SBH8-K8> to 0.11 cent, from Monday's high of 0.27 cent.
* March open interest sat at 36,379 lots on Monday and a heavy 25,388 lots traded on Tuesday, data showed.
* A reasonably large delivery of around 1 million to 1.1 million tonnes was anticipated, dealers said, with one European analyst expecting Brazil and Guatemala to be among the origins.
* "The trade chat has been revolving around the explanation of possible priorities for the coming Brazilian campaign to be leaning more to ethanol over sugar production and so taking sugar from the H18 tape (March futures) is viewed as strategic in that contingency," said Thomas Kujawa, co-head of softs at Sucden Financial.
* India's sugar production is likely to rise to a record 29.2 million tonnes in the 2017/18 season, a survey showed.
* May white sugar settled down $8.90, or 2.5
percent, at $350.50 per tonne, after falling to $349.50, the lowest since September 2015.
* May London cocoa settled up 12 pounds, or 0.8 percent, at 1,576 pounds per tonne, after rising to a three-month high at 1,582 pounds.
* May New York cocoa settled up $12, or 0.5 percent, at $2,227 per tonne, having reached a 13-month high at $2,234.
* A diminished crop outlook in top grower Ivory Coast supported prices, dealers said.
* The International Cocoa Organization is expected to publish its first forecast for the global balance in 2017/18 on Wednesday.
* May arabica coffee settled down 0.8 cent, or 0.66 percent, at $1.211 per lb.
* May robusta coffee settled down $9, or 0.5 percent, at $1,735 per tonne. The March premium over May <LRCH8-K8> rose to a contract high at $49.
(Reporting by Marcy Nicholson in New York and Nigel Hunt in London, additional reporting by Chris Prentice in New York Editing by Dale Hudson and Cynthia Osterman)