Nippon Oil Corp. bought 55 percent of a lubricant producer from Italy's Eni SpA and Singapore Petroleum Co. in an effort to boost sales in Southeast Asia.

ENEOS ItalSing Pte. operates a plant in Singapore with production capacity of 50,000 tons a year. Eni subsidiary Eni International BV and Singapore Petroleum each retain 22.5 percent stakes, Nippon Oil said Thursday.

The purchase is the latest by Nippon Oil, Japan's biggest refiner.