The new Glencore, which has systematically analysed the profitability of its coal mines since the merger with Xstrata, blamed the closure on increasingly difficult economic conditions the mine is experiencing.

It follows a number of changes introduced over the past year in an effort to improve the mine’s viability, the company said.

“These changes were communicated to employees last May and included a move from seven to five-day rosters, and reductions in the number of development crews, maintenance, support and services functions.”

A Glencore spokesman said continued operations were no longer financially viable due to a combination of lower prices, high production costs at the mine, a strong Australian dollar and geological constraints in future mining areas.

Ravensworth underground employs 130 full-time employees and three contractors.

Redeployment options across the company’s other mining operations are being investigated.

Mining will finish once the extraction of Longwall block 9 is completed. The mine will then be placed on care and maintenance, with a small full-time workforce remaining to manage the mine.

Ravensworth Underground began production in 2007. It has been managed by Glencore since February 2008 and is a joint venture operation between Resource Pacific Pty Limited (owned by Glencore and Marubeni) and Posco (a Korean steel manufacturer).

As majority shareholder of Resource Pacific, Glencore oversees the management of the mine.

Ravensworth underground produced 2.1 million tonnes of saleable semi-soft coking coal in 2013.

Glencore increased its annual Australian coking coal production in 2013 by 6% to 7.3Mt as the company focused on resolving longwall problems at its Oaky Creek complex in Queensland.

The company believes it could have increased production even more but strategically slowed down the ramp-up during the low coking coal price period.