Cokal announced it has secured the funding to pursue its Bumi Barito Mineral project.
The area was described as one of the planet’s richest treasure troves by the World Wildlife Foundation.
The company plans to mine 200 million tonnes of coking coal from the BBM project over the next decade.
The project is one of five coalmines Cokal hopes to develop in the Central Kalimantan province.
The company has permits covering 62,000 hectares of land, some within the borders of the Heart of Borneo.
The HoB initiative is recognised by the governments of Malaysia, Brunei and Indonesia.
In 2007, each of the countries signed an agreement to protect the largest remaining stretch of trans-boundary forest in Southeast Asia from the degradation caused by logging, oil palm plantations and mining.
Indonesia mined 421Mt of coal last year, the majority from Kalimantan.
The national government has also agreed on a public-private partnership to build a coal railway from the interior of the province to the port, estimated to boost coal production in Central Kalimantan six-fold.