Japanese insurers are planning to hike premiums for coverage of war damage to ships in waters around Russia and Ukraine.
The move comes as Russia's drawn-out invasion of Ukraine prompts reinsurance companies to increase their rates.
Sources say three non-life insurers will raise their premiums by about 80 percent from late January.
The companies are Tokio Marine & Nichido Fire Insurance, Sompo Japan Insurance and Mitsui Sumitomo Insurance.
Last month the firms said they would stop offering war-risk insurance in waters around the conflict zone because reinsurers were withdrawing their coverage.
But they later backtracked, and said they would extend their protection until March.
Ship owners need war-risk insurance because standard insurance doesn't cover them for damage from military conflicts.
Japan uses ships to import liquefied natural gas from the Sakhalin-2 oil and gas project in Russia's Far East.
The government is concerned that the suspension of war-risk insurance could impact the stable supply of LNG.