The company has been in talks with undisclosed parties to sell the unit as part of its drive to raise money as it bleeds cash due to low coal prices on the global market.
"We are in the final phase of discussions with potential buyers and I expect that the transaction will be completed in the coming months," NWR board member and executive director Jan Fabian said in a television debate.
He said the company would seek a deal under which the buyer would continue to take some coal supplies from NWR.
"This is one of the basic pillars of the agreement," he said.
Poland's JSW (JSW.WA) said earlier this year it was looking at some NWR assets, while Czech news website www.aktualne.cz has reported that Czech businessman Petr Otava was interested in the coking plant.
Fabian also reiterated the firm's decision to close down its Paskov hard coal shaft close to the city of Ostrava at the end of 2014, despite government calls to extend mining there at the company's own cost until 2016.
He said mining could only continue if the government took on losses from the mine. But he said he would take part in talks with government officials on how to resolve the situation of about half of Paskov's 3,000 miners who risk losing their jobs.
Tens of thousands of Czech miners have lost jobs in the past two decades in a restructuring of the country's mining and heavy industries.
Reporting by Jan Lopatka; Editing by Mark Potter