The maker of America's top sugar brand, Domino Sugar, is launching its first no-calorie "natural" sweetener extracted from the stevia plant in Paraguay, the strongest sign yet that the upstart product is threatening to eat into demand for sugar.

In less than a decade, the sweet-tasting stevia powder has stolen a big chunk of the $1.3 billion global market for artificial sweeteners as more health-conscious consumers use it in what they eat and drink.

Consumers' appetite for artificial sweeteners like Cumberland Packing Co.'s Sweet'N Low and corn syrup has waned amid rising interest in foods perceived as natural.