Shin Mitsui Sugar Co. and Fuji Nihon Seito Corp. said Friday they have agreed on a business tieup under which Shin Mitsui will handle sugar production to make up for the closure of a Fuji Nihon Seito sugar refinery.

The deal is the latest of a series of business alliances among Japanese sugar refiners amid a decline in demand due to the growing popularity of low-calorie sugar substitutes.

Under the agreement, Shin Mitsui will cooperate with the medium-ranked sugar refiner in closing Fuji Nihon Seito's refinery in Shizuoka, the two sugar refiners said.