Wheaton will pay an upfront deposit of US$175.5 million, of which US$13 will be available before construction, and US$0.5 million will go to community development around the mine. The remainder will be paid in installments during construction of the project, subject to various conditions.

The deal will see Wheaton International take 50% of the payable gold production referenced from Curipamba, dropping to 33% for the life of mine once 150,000 ounces of refined gold have been delivered, and 75% of the payable silver production, dropping to 50% for the life of mine once 4.6Moz of refined silver have been delivered.

Attributable production is forecast to average 17,000 oz of gold and 551,000 oz of silver per year for the first five years of production.

Wheaton will make a production payment of 18% of spot price for the gold and silver delivered. Once the value of metal delivered, minus production payment, is equal to the deposit, the payment will increase to 22% of the spot price.

Wheaton will fund the deal with cash on hand, loan facilities, and cash flow.

Adventus, together with its Curipamba partner Salazar Resources, said Monday they had a total of US$235.5 million in funding, a figure sufficient to see the project built.

In addition to the Wheaton deal, the pair have also secured a US$55 million commitment from Trafigura, giving them a total of US$23.5 million for pre-construction activities.

The addition of the Curipamba stream will boost Wheaton's estimated proven and provable reserves by 0.26Moz of gold and 7.1 Moz silver.

"Forecasted to be a high quality, low-cost mine with significant exploration potential, Curipamba's profile aligns well with Wheaton's accretive growth strategy," said Wheaton CEO Randy Smallwood.