Vancouver-based Wheaton Precious Metals has agreed to purchase future silver output from BHP’s share of the Antamina copper-zinc mine, located north of Lima, Peru, in a US$4.3 billion silver streaming deal, the companies announced this week. 

Under the agreement, Wheaton will make the upfront payment of US$4.3 billion on completion of the agreement, which is expected around April 1, and will pay 20 per cent of the spot silver price for each ounce delivered. 

BHP, through a wholly owned subsidiary, will deliver its 33.75 per cent portion of the silver produced as a byproduct at the Antamina mine to Wheaton until 100 million ounces are reached. After that, the stream will be reduced to 22.5 per cent of Antamina’s silver production for the remainder of the mine’s life. At present, the mine’s estimated reserves support operations through 2036, with the possibility of extending the mine life with further expansion and exploration.  

BHP holds a 33.75 per cent interest in Compañía Minera Antamina (CMA), the joint venture that independently operates the Antamina mine. CMA is not a party to the streaming agreement, said BHP in a Feb. 17 press release, adding that its shareholder rights and joint venture obligations remain unchanged. The remaining shareholders of CMA are Glencore (33.75 per cent), Teck Resources Ltd. (22.5 per cent) and Mitsubishi Corporation (10 per cent). 

Wheaton is recognized as pioneering the precious metals streaming model, an alternative financing structure in which a miner receives upfront capital in exchange for delivering a fixed portion of future production (often a byproduct metal) at a discounted price. 

In 2015, when the company was operating under its former name Silver Wheaton Corp., it entered into a separate US$900 million streaming agreement with Glencore, which entitled it to Glencore’s 33.75 per cent share of Antamina’s silver output.  

As a result of these agreements, Wheaton will now receive a combined 67.5 per cent of all silver produced at Antamina. 

“Deepening our exposure to an asset of this scale, quality and longevity is a unique and transformative opportunity for Wheaton,” said Wheaton president Haytham Hodaly in a Feb. 16 press release, describing Antamina as a “proven, long-life, low-cost operation” that is expected to generate immediate production and operating cash flow. 

Outgoing CEO Randy Smallwood added that the agreement reinforces Wheaton’s standing as one of the world’s largest silver producers. 

The additional streaming agreement with BHP is expected to contribute an average attributable production of roughly six million ounces of silver annually to Wheaton over the first five years and an average of 5.4 million ounces per year over the first decade. When combined with its existing Glencore stream, Antamina is projected to deliver approximately 12 million ounces per year to Wheaton during the first five years. 

Meanwhile, for BHP, the deal allows the company to monetize silver while maintaining full exposure to copper, zinc and lead production from its stake in the operation. The company said the agreement is not expected to increase its reported debt levels. 

BHP CEO Mike Henry said the deal “further unlocks additional value from the asset in an innovative and disciplined way,” while chief financial officer Vandita Pant described it as part of BHP’s active capital management strategy aimed at enhancing balance sheet flexibility, supporting long-term value creation and delivering shareholder returns. 

In 2025, Antamina’s total production was 368,000 tonnes of copper, 383,407 tonnes of zinc and 16 million ounces of silver.