Mining Press Roundup: Diamond Slump Forces Ownership Changes at Petra and Mountain Province

Mountain Province Diamonds has agreed to give De Beers full ownership of the Gahcho Kué mine in Canada, and Petra Diamonds has opened a strategic review that could end in a sale. The two announcements landed in the same news cycle and point the same way: the diamond slump is now changing who owns the mines. For Mountain Province, the deal is a restructuring that ends its direct stake in its main asset. For Petra, the review follows liquidity pressure, a closing mine and a tax petition. Elsewhere, Sigma Lithium has halted its only producing complex, and KGHM and South32 have started a large copper expansion in Chile.

Mountain Province Diamonds: Gahcho Kué Goes to De Beers in Restructuring

Mountain Province entered a consensual restructuring implementation agreement with De Beers Canada, lender Dunebridge Worldwide and the holders of its senior secured lien notes due December 2027, according to Mountainprovince. Under the agreement, De Beers assumes full ownership of the Gahcho Kué diamond mine in the Northwest Territories. It obtains Mountain Province's 49% participating interest in satisfaction of the remaining reclamation payments and all other debts owing to De Beers. Mountain Province says those reclamation payments represent its share of the decommissioning, reclamation and environmental clean-up costs at the mine.

CEO Jonathan Comerford attributed the "material decline in diamond prices over the past year" mainly to tariff-related uncertainty and the conflict in the Middle East. He said the deal "provides the most credible path to protect stakeholder value in the current circumstances."

The noteholders and Dunebridge agreed to a six-month period in which interest and capital repayments and the exercise of specified rights are suspended. Mountain Province keeps a foothold. Its JVCo subsidiary gets a right of first offer and a right of first refusal if De Beers elects to sell all or substantially all of the mine or its mineral rights. The company also says it controls more than 96,000 hectares of mineral claims and leases surrounding Gahcho Kué.

MINING.COM reports that the restructuring shows weak prices, sluggish demand and competition from lab-grown stones forcing producers to cut costs, curb output and reconsider how they operate.

Petra Diamonds: Strategic Review Opens the Door to a Sale

Petra Diamonds (LON: PDL) is considering a potential sale as part of a strategic review aimed at addressing liquidity pressures, MINING.COM reports. The publication links the review to a prolonged diamond-market downturn and operational challenges at the Finsch mine in South Africa. Petra said Thursday the review would consider all available options as it seeks to strengthen its financial position. It followed consultations with key stakeholders, including first- and second-lien creditors, and could bring the flagship Cullinan mine near Pretoria into play.

The market reacted sharply. Petra shares dropped almost 20% on the news, leaving the company with a market value of £19.1 million ($25.2 million). Petra also announced that José Manuel Vargas has stepped down as chair, with insider Lerato Molebatsi taking over on an interim basis.

The balance sheet adds to the pressure. Net debt rose to $322 million at the end of June from $298 million three months earlier. In July, Petra deferred about $6 million in cash interest until January 2027. Its financing arrangements required refinancing talks to begin in September, with the goal of agreeing non-binding commercial terms by the end of October.

A winding-up petition adds a legal strand. It targets Petra Diamonds UK Treasury, a wholly owned indirect subsidiary, over £5.65 million ($7.5 million) in unpaid UK corporation tax for the year ended June 30, 2025. A High Court hearing is scheduled for Oct. 14. Petra said both subsidiaries involved are non-operating companies that do not own or run any of its mines.

Finsch is being closed after business rescue practitioners concluded there was no reasonable prospect of rescuing the operation.

The supply picture frames both stories. Analyst Paul Zimnisky estimates global natural diamond production will fall to about 90 million carats this year, "the lowest level since 1987." That compares with more than 150 million carats only a few years ago. Zimnisky also sees early indications of support for rough diamond prices that could eventually underpin a recovery in mined stones.

Sigma Lithium: Operations Halted at Grota do Cirilo

Sigma Lithium (TSXV, Nasdaq: SGML; ASX: SAU) has halted all mining and processing at its Grota do Cirilo complex in Brazil. The stoppage came two days after the company dismissed reports that a court had suspended the operation's environmental licences. Grota do Cirilo is Sigma's only producing asset, with annual lithium concentrate capacity of 330,000 tonnes.

A federal judge suspended the complex's environmental licences and mining operations on Sept. 4 in a civil suit filed by the Federation of Quilombola Communities of Minas Gerais, known as N'Golo. Sigma's Toronto shares fell 19% to C$11.16 by mid-Thursday, leaving them about 40% lower this year.

The company kept its 2027 guidance at 330,000 tonnes but delayed its 240,000-tonne 12-month production target. BMO analyst Joel Jackson cut his 2027 production estimate for Sigma to 207,000 tonnes from 278,000 tonnes. The LIT lithium ETF closed at $68.22 on Oct. 1, down 0.3%, according to market data.

KGHM and South32: Sierra Gorda Expansion Under Way

KGHM and South32 have officially begun a $725 million expansion of their Sierra Gorda copper mine in Chile. It is expected to lift annual copper output to nearly 200,000 tonnes. A fourth grinding line will increase ore-processing capacity by 26%. Construction is scheduled to begin in January 2027, with full capacity expected in the second half of 2030.

According to South32's investment approval announcement, the project targets average annual payable copper production of about 195,000 tonnes and a roughly 10% reduction in average operating unit costs. Per Polygon data, the COPX copper miners ETF closed at $83.40 on Oct. 1, down 1.5%.

Grid Metals: Falcon West Cesium Resource Takes Shape

Grid Metals (TSX: GRDM) outlined an initial resource that positions its Falcon West property in Manitoba as the world's second-largest cesium resource actively being developed by Western-based companies. The Lucy South deposit holds 51,500 tonnes grading 2.58% cesium monoxide and 1.47% lithium oxide, for contained metal of 1,322 tonnes Cs2O.

The entire Lucy South resource is classified as measured, the highest-confidence category under Canadian mineral resource reporting standards. Grid holds an 85% interest in Falcon West and operates the joint venture with Agnico Eagle Mines' Avenir Minerals unit, which owns the remainder.

DPM Metals: Vareš Keeps Running After Court Ruling

DPM Metals (TSX, ASX: DPM) said its Vareš operation in Bosnia and Herzegovina continues to run normally. The Constitutional Court had found its concession agreement and related land decisions unconstitutional. The court published its full decision on Sept. 30, giving authorities six months to review the challenged acts. DPM said the decision is final and cannot be appealed.

First Quantum Minerals: Shares Slide on Panama Recommendation

First Quantum Minerals shares plunged as much as 36% in early trading in Toronto. A ministerial committee had recommended that Panama negotiate a restart of Cobre Panama to fund its eventual orderly closure.

What It Means

The diamond sector is the clearest theme today. Mountain Province is handing a flagship asset to its partner and keeping only first-offer and first-refusal rights. Petra is exploring a sale with creditors involved, a closing mine and a tax petition pending. Zimnisky's note on shrinking output and early price support suggests the supply side is adjusting. But the pressure on balance sheets is arriving first, and the ownership changes look likely to continue until prices recover.

Outside diamonds, today's announcements show how much project risk depends on outside decisions. A court order has idled Sigma's only producer. A constitutional ruling hangs over Vareš even as operations continue. A ministerial recommendation moved First Quantum's shares sharply. Against that, the Sierra Gorda expansion shows capital still committing to copper where the schedule runs to 2030, and Grid Metals shows juniors still defining critical-mineral resources.

This roundup covers press releases published on October 2, 2026. Company announcements are sourced from mining industry wire services. For corrections or updates, contact contact@stakeandpaper.com.