The news traces back to a report by Inside Coal, which cited a person “familiar with northeast British Columbia”.
Bloomberg reported that Walter had not responded to its requests for comments.
Walter shares reportedly climbed 5.7% on the news yesterday.
Western Coal operates three metallurgical coal mines in Canada.
Walter’s $US3.2 billion ($A3.5 billion) acquisition of Western Coal was expected to make it the top publicly traded pure-play metallurgical coal producer in the world with access to the Pacific and Atlantic seaborne markets.