TOKYO -- Tokio Marine Holdings will stop underwriting and financing coal mining projects that generate thermal power in Japan and abroad from October, Nikkei has learned, a move likely to be followed by other domestic insurers.

Without insurance against accidents, natural disasters, fires and construction-related mishaps, coal miners will find it hard to operate. Tokio Marine will be the first Japanese insurer to pull out of the business. Western insurers, such as Germany's Allianz, have already taken such steps.

Japan's top three casualty insurers -- Tokio Marine, Sompo Japan and Mitsui Sumitomo -- decided last year to stop underwriting coal power projects. Now that Tokio Marine has made the move, Sompo and Mitsui Sumitomo are likely to follow, which will stop such projects from going ahead.

The coal mining market was worth $661.6 billion in 2020, up 15% from 2015, according to market research company IBISWorld. Some 70% of the total was in supplying fuel to power companies.

Japan's insurers made revenue of around 10 billion yen ($91 million) a year from underwriting coal mining projects.