* Asia Q3 cocoa grind drops 1.6 percent year-on-year

* Brazil cane crush data due later on Friday

By David Brough

LONDON, Oct 23 (Reuters) - ICE raw sugar futures hit an eight-month high on Friday as rains slowed cane crushing in Brazil, while cocoa edged up, supported by better-than-expected grindings data from Asia.

Arabica coffee futures fell to a three-week low as Brazilian rains boosted crop prospects in the world's top producer of coffee and sugar.

ICE March raw sugar was up 0.06 cent, or 0.4 percent, at 14.66 cents per pound at 1108 GMT, after rising as high as 14.73 cents, the loftiest since Feb. 20.

Dealers said rainfall linked to a strong El Nino was already slowing sugar production in Brazil and the outlook for above-average precipitation in the key centre-south growing region was helping to support prices.

Brazilian cane crush data for the first half of October is expected to be issued later on Friday although the impact of rains is likely to be more significant in the second half of this month.

Nick Penney, senior trader with Sucden Financial, said the report was "expected to show a higher cane tonnage crush total than is usual for the period, given the relative lack of days lost to rain."

"It is expected to be a bearish report although it may now be superseded by expectations for the second half of October given the days already lost and expected to be lost given the rain forecast in the period," he said.

Tom McNeill, director of analyst Green Pool, said he expected around 36.5 million tonnes of cane were crushed in the first half of October, and that in some of the wetter areas, five or six days of crushing may have been lost due to rains.

December white sugar traded up $2.90, or 0.7 percent, to $393.80 per tonne.

December New York cocoa traded up $12, or 0.4 percent, at $3,152 per tonne, supported by the Asian cocoa grindings figures.

The third-quarter Asia grind fell by 1.6 percent, year-on-year.

Dealers said a decline of about 5 percent had been generally expected.

ICE March London cocoa was up 14 pounds, or 0.7 percent, at 2,138 pounds per tonne.

December arabica coffee was down 0.2 percent at $1.1965 per lb, its lowest level since Oct. 2 as recent rains brought relief after a dry spell that threatened to damage the flowering of Brazil's crop.

January robusta coffee was down $6, or 0.4 percent, at $1,580 per tonne. (Additional reporting by Nigel Hunt; Editing by Dale Hudson)