Dartbrook (Underground) is a suspended mine in the upper Hunter Valley in New South Wales. The underground mine commenced operations in 1995 and was closed in 2006. This asset report covers the potential re-start of underground operations at Dartbrook, exporting thermal coal. For the separate proposed surface project, please refer to the Dartbrook asset report. In December 2015, Australian Pacific Coal announced a conditional agreement to acquire Anglo American's majority stake in the joint venture. In May 2016, an agreement was also announced to move to 100% ownership by acquiring Marubeni's interest. The transaction completed at the end of May 2017.