South Korea wants to guarantee its coal supplies through a state and private sector venture with a $2.1bn(£1bn) Russian mining project.
South Korea is looking to Sakha to solve its energy needs
Industrial group LG International and state-run Korea Resources Corp intend to participate in the expansion of a mine in the Russian Republic of Sakha.
South Korean power generators are concerned about delays in coal supplies from traditional partners like China.
The Sakha mine could propel Russia to the front rank of Seoul's coal sources.
South Korea imports 27 million tonnes of coal from Australia every year, and 17m tonnes from Indonesia.
Russia provides South Korea with 4.8 million tonnes of coal annually, but the Sakha mine has the potential to produce 30 million tonnes a year.
The mine, known as the Elga project, should reach peak production by the end of 2009.
Strong domestic demand in supplier nations has restricted South Korea's access to coal in recent years and boosted the importance of energy security in Seoul.
Sakha, also known as Yakutia, is in Eastern Siberia and holds 45% of Russia's entire coal reserves. It is the second largest coal deposit in the world.
LG International already holds a 35% stake in a separate Russian coal mine.