Glencore has confirmed it will cut 100 jobs by the end of next month at its Newlands open cut coal mine.
The miner stated "the decision has been taken as a result of ongoing difficult market conditions".
As part of this worker reduction the mine will also reduce production.
However Glencore did note "the mining complex will continue to support a workforce of more than 650 after the changes are implemented".
"Where vacancies exist we will explore options for redeployment across out Australian coal operations as well as putting in place support services for affected employees and their families".
The CFMEU were contacted but were unavailable for comment at the time of publishing.
This is not the first major shakeup of the workforce at the site.
In June it announced that it would close the Newlands Northern underground coal mine at the complex.
According to the miner it is shutting down the operation as it comes to the end of its mine life in 2015.
"As part of the process toward the mine's closure, development activities will cease at the end of June 2014 following the establishment of the final longwall panel," Glencore said at the time
Completion of these development activities resulted in the reduction of around 50 positions at the site.
Last year Glencore, (then Xstrata), also reduced its open cut operations from three mining areas into one, affecting approximately 300 open cut and underground workers at the time.
It began informing workers of the latest reduction today, adding that it is reviewing all of its coal operations during this difficult economic climate.