The figures also underscore improved energy efficiency, and the emergence of alternative fuels for power generation and in transport, while a rise in nuclear power output last year in Japan further reduced fossil fuel imports.

Japan's customs-cleared crude oil imports slid 5.8 percent in 2018 from a year earlier, the Ministry of Finance said on Wednesday.

Japan, the world's fourth-biggest crude buyer, imported 3 million barrels per day (bpd), or 175.897 million kilolitres, of crude oil last year, the preliminary data showed. The figure marks the lowest since records were kept starting in 1979, an official at the customs office said.

Despite this, import costs jumped 25 percent from a year earlier due to higher average annual prices for crude oil.

Imports of LNG slid 0.9 percent to 82.854 million tonnes, the lowest since 2011, but their value increased 21 percent.

Japan is the world's biggest importer of LNG, or gas chilled to liquid form for transportation on ships.

Imports of thermal coal for power generation declined 0.6 percent

in 2018 to 113.670 million tonnes, the data showed.

The following tables lay out Japan's fossil fuels imports for December and for all of 2018, with volumes of crude in million barrels per day (bpd), oil products and gasoline/naphtha in million kilolitres, LNG, LPG and coal in million tonnes and values in millions of yen.

(Reporting by Yuka Obayashi; editing by Christian Schmollinger)