Mechel signed the final agreement to buy the U.S. privately-owned company on April 22.
The $436 million sum includes $36 million in interest payments, Mechel's $83.3 million-worth of preferred shares, plus the obligation to pay off around $132 million in company debts.
However, the deal does not include other businesses run by the owners of Bluestone Coal Corp., which include steam coal operations in Kentucky and non-coal activities.
As part of the deal the parties are expected to float preferred shares as soon as the market conditions are favorable.
Bluestone, a New York-traded company controlled by billionaire Igor Zyuzin, produced 2.8 million metric tons of hard coking coal in 2008, with total sales of some $327 million.
Mechel is one of the Russia's leading companies, uniting producers of coal, iron ore, concentrate, nickel, steel, rolled products, hardware, and thermal and electric power.