Japan is looking to suspend or close as many as 100 older, inefficient coal-fired power plants by about 2030, the Yomiuri daily newspaper reported on Thursday.

Closures on that scale would mark a major shift in the government's strong support for coal in the world's third-biggest economy. Japan is the only Group of Seven nation to be rolling out plans for new coal power stations, a major contributor to carbon and other emissions that stoke global warming.

Without citing sources, the Yomiuri said industry minister Hiroshi Kajiyama is set to announce soon that nearly 90% - about 100 - of 114 power plants built before the mid-1990s and deemed inefficient by the government will be closed or mothballed.

Contacted by Reuters, an official at the Ministry of Economy, Trade and Industry (METI) confirmed the government views 114 of Japan's 140 coal-fired plants as inefficient. The official said Japan has set out plans to phase out inefficient coal power plants by 2030.

"But we have not made any decisions to retire or suspend 100 plants," the official said.

Coal accounts for 32% of Japan's energy supply mix and the country needs to take "firm measures" to get that level to a target of 26% by 2030, another METI official said on Wednesday, speaking at a meeting of a panel to discuss resource and energy policy.

Japan has come in for criticism from non-governmental organisations, some other nations and, recently, major Japanese companies like giant supermarket retailer Aeon Co. for its reliance on fossil fuels.

The world's third-biggest economy ramped up coal use to record levels after the Fukushima nuclear disaster in 2011 led to the shutdown of most atomic reactors, which once supplied about a third of Japan's electricity.

(Reporting by Chang-Ran Kim, Ritsuko Shimizu and Yuka Obayashi; Writing by Aaron Sheldrick; Editing by Uttaresh.V and Kenneth Maxwell)