Alliance Resource Partners bought the stake from White Oak Finance and other parties, making the company the sole owner of White Oak Mine No. 1.
Upon closing of the transaction, Alliance Resource subsidiary Alliance WOR Processing will take over operations of the White Oak Mine No. 1, and Alliance Resource will own 100 % of the equity interests in White Oak.
Located in Hamilton County, Illinois, the White Oak Mine No. 1 is an underground longwall mining operation, which produces high-sulfur coal.
The mining process began last October last year and it is expected to produce 6 million tons of coal per annum.
Alliance Resource Partners president Joseph W. Craft III said: "Strategically, owning 100 percent of White Oak and assuming operating control of the White Oak Mine No. 1 enhances our already strong presence in the Illinois Basin.
"The White Oak mine is a world-class, low-cost longwall operation with an extensive reserve base. It will be an attractive addition to our asset portfolio and provide ARLP increased flexibility to service our existing customer base and the opportunity to expand into additional markets.
"In the near term, White Oak gives us greater optionality to optimize our production to current market conditions."