Moolarben Coal Operations Pty Ltd (MCO) is the operator of the Moolarben Coal Complex on behalf of the Moolarben Joint Venture (Moolarben Coal Mines Pty Ltd, Yancoal Moolarben Pty Ltd and a consortium of Korean power companies). MCO, Moolarben Coal Mines Pty Ltd and Yancoal Moolarben are wholly owned subsidiaries of Yancoal Australia Limited.