OKD CEO Dale Ekmark said that the firm plans to lay off 5,000 to 6,000 jobs in the next two years as part of its restructuring plan.
The firm, which currently has 12,828 staff, including 3,013 agency workers, also intends to close three mines to face the weak coal prices.
The job cuts decision comes after the Czech Government rejected to grant a four billion crown bailout package in 2015 to OKD.
NWR is currently negotiating with the government on reorganizing to reduce by closing its Paskov, Lazy and Darkov mines as well as to secure new funding.
Reuters cited Ekmark as saying: "We would like to create a slimmer organization that would be sustainable in this new environment of long-term low coal prices.
"With regard to the future size of OKD, 5,000 to 6,000 employees looks like an economically viable number."
Although NWR restructured its debt and equity in 2014, it struggled to generate cash due to a fall in coal prices.
Ekmark noted that the OKD, however, will continue to operate other coal mines, which secured approval from Environment Ministry for extended mining until 2023 in the county.
