In March, a report compiled by the Ministry of Economy, Trade and Industry on greenhouse gas emissions of about 9,000 companies rocked the electric power industry.

Of the 20 worst polluters, 11 were electric power companies, with Tokyo Electric Power Co. ranked at the top with 68.88 million tons of carbon dioxide spewed out in fiscal 2006, the report said.

METI's report, which was published for the first time but will from now on be compiled annually, was meant to pressure companies to work harder to slash greenhouse gases.