Barrick Gold Corp. has offered an extra 15 percent stake in its Porgera gold mine in Papua New Guinea to local landowners, according to a letter from its CEO, in a bid to break an impasse with the national government over the mine’s future.

Last month, Barrick, the world’s second-largest gold miner, was refused an extension of its expired lease over the mine that has been troubled by social unrest and pollution concerns, reported Reuters.

Any deal would be the first struck by a resources company under economic nationalist prime minister, James Marape, who came to power a year ago seeking to retain a bigger share of the country’s resource riches. Talks between the government and Exxon Mobil over a gasfield broke down in February, leaving a proposed $13 billion gas project expansion in limbo, while Australia’s Newcrest Mining Ltd. is in talks on a major gold project.

The government’s position on Barrick’s offer is unclear. Marape’s office did not immediately respond to a request for comment and he has previously expressed a desire for the state to operate the mine itself.

Barrick is challenging the rejection of its lease extension in court. However, negotiations have also proceeded via back channels after Marape, appointed the district’s local member, Tomait Kapili, as a go-between.

“In light of the prime minister’s positive engagement through you, we would like to go further and improve the equity portion of the ... offer to 15 percent free equity, for a total of 20 percent equity to be held by the PNG side including the 5 percent currently owned,” Barrick’s chief executive officer Mark Bristow wrote to Kapili last week, in a letter reviewed by Reuters.

Kapili does not have the authority to accept or refuse the offer because Marape appointed him only to deal with matters relating to local landowners, a separate letter from Marape to Kapili and reviewed by Reuters showed.

Kapili and Barrick did not immediately respond to requests for comment on Friday. A spokesperson for the joint venture, Barrick Niugini Ltd., declined to comment because the case was before court.

Barrick and China’s Zijin Mining Group each own 47.5 percent of the Porgera mine high in mountainous Enga province, about 600 km (375 miles) northwest of the capital Port Moresby. The remaining 5 percent interest is held by landowners through Mineral Resources Enga.

Bristow’s letter added that Barrick was willing to further increase the landowners’ equity stake, but only if other terms such as corporate taxes were relaxed.

He said over the 20-year mine life, PNG would receive $4.7 billion in cash flow, compared with $3.5 billion for the joint venture, based on a long term gold price of $1,300 an ounce. Gold prices hit 7.5-year highs above $1,750 an once this month.