The assets to be sold are Cliffs’ interests in the Sonoma mine including its ownership of the affiliated wash plant.

Cliffs Natural Resources chairman, president and chief executive officer Joseph Carrabba said, "This transaction reinforces our strategy to direct management and capital resources towards long-lived expandable assets where Cliffs has operational control."

Apart from QCoal, the Sonoma joint venture has three other players, JS Sonoma, CSC Sonoma and Watami (Qld).

In 2011, Sonoma coal mine production and sales volumes were 3.5 million and 3.1 million metric tons of coal, respectively.

The product mix is nearly two-thirds thermal coal and one-third metallurgical coal.

The company anticipates the deal to close during the fourth quarter of 2012.

Cliffs said there will not be any change in the management and the existing manager Sonoma Mine Management will continue to oversee the operations.