The Globe and Mail reports in its Saturday edition that Barrick Gold and a Chinese partner on Friday said they would challenge Papua New Guinea's apparent move to grant a 20-year lease for the Porgera gold mine to a state-backed firm, the latest escalation in their dispute with the country. A Canadian Press dispatch to The Globe says that Barrick Niugini Ltd. (BNL), the joint venture that operates Porgera, said in a statement that it would challenge the "purported grant" of the special mining lease by PNG Prime Minister James Marape to state-owned Kumul Minerals Holdings Ltd. as "unlawful and invalid." Barrick stopped production at Porgera and sued PNG's government after it refused to extend the mine's lease in April because of community unrest and pollution concerns. A prolonged shutdown could jeopardize the mine's future, Barrick chief executive officer Mark Bristow has said. In its release, BNL said it "will take steps to challenge the purported grant" on Aug. 25 of a 20-year mine lease to Kumul. Barrick declined to comment on what those steps would entail. The Canadian miner in July served a dispute notice to the PNG government and said it would seek international arbitration to resolve the impasse.