Japanese ethylene production rose 0.1%  in March from the same month a year earlier, although some plants were shut after the March 11 earthquake, government data showed on Thursday.

Ethylene output totaled 514,800 tons last month compared with 514,100 tons a year earlier, the Ministry of Economy, Trade and Industry said.

March output was down 15% from 605,300 tons in February, when no plants were shut for maintenance.

There was one maintenance-related plant shutdown in Japan in March, while three plants were shut in the same month last year, METI said.

Maruzen Petrochemical and JX Nippon Oil & Energy, an oil refining unit of JX Holdings, have restarted their quake-shut naphtha crackers, leaving two crackers still shut at the Kashima plant operated by Mitsubishi Chemical Corp, with a total ethylene making capacity of 828,000 tons per year.

Ethylene, made from naphtha, is a basic feedstock for petrochemicals that are processed into products such as plastics. The export volume of ethylene fell 9.6% to 191,800 tons in February from a year earlier. The January export figure was 211,300 tons. March export figures have not yet been released.