Brasil's cane growers will harvest the smallest crop in four years because of dry weather and frost.
Brasil accounts for about 54% of the world's sugar exports.
Colombia reports that arabica bean exports have fallen to their lowest level since 1988 in August after storms battered crops.
Exports fell 38% to 374,000 bags from 599,000 bags in August 2010.
Production is expected to increase this month, however.