The decision has been made as a result of continued low prices in global coal markets, which has meant the economic return from reserves still available at Tahmoor are not sufficient to warrant the investment required to mine them, Glencore said in a statement.
Glencore has a policy of reducing production output during periods of low prices.
The mine, which has been operating since 1979, last year produced 2.1 million tonnes of saleable metallurgical coal.
The workforce of 350 will be gradually reduced over the next 18 months as development work at the mine is completed, Glencore said. All mining is expected to end by early 2019.
A number of options to continue operations were examined, including the proposed Tahmoor South and Tahmoor North projects, but current market conditions do not support these projects, the company said.
“We appreciate this will be a difficult time for our employees and we will be putting support services in place to assist them, including investigation of opportunities for redeployment at other Glencore coal operations,” it said.
Mining consultant and industry veteran Brian Nichols told ICN: “This is a sad day for me, as I built and opened the mine more than 30 years ago and ran it for nearly 10 years.”