The biggest steel producer of ArcelorMittal Monday said, to buys exploration company of coal mine US, Mid Vol Coal. Price of purchasing is not mentioned.

Mid Vol Coal is coal mining company US being based on in Virginia and West Virginia. One year ago this company had capacity produce of coal 1.5 million ton, and has coal reserves 85 million tonnes which would soon in exploration and production.

“This acquisition further increases our upstream self-sufficiency in a primary raw material,” said finance director Aditya Mittal in a statement.

ArcelorMittal is the biggest buyer of Mid Vol’s coking coal, used to produce coke, which is a key raw material required in the steel-making process.

The acquisition fits with the company’s strategy of buying mining groups to acquire its own supply of raw materials at a time of rapidly rising prices.

The company, controlled by Indian-born steel tycoon Lakshmi Mittal, has recently bought stakes in South Africa’s Coal of Africa, Australian mining group Macarthur Coal and has bought three mines in Russia.