The operation is part of the Japanese company's asset portfolio re-composition. The firm intends to focus on the advanced materials business, such as sputtering cathodes for semiconductors, while managing the volatility of its resources business.

apan's JX Advanced Metals, a unit of Eneos Holdings 5020.T, said on Wednesday it has agreed to sell an additional 19% stake in the operator of Caserones copper mine in Chile to Canada's Lundin Mining LUN.TO for $350 million.

The deal will reduce JX's stake in the operator, SCM Minera Lumina Copper Chile (MLCC), to 30% from 49% while boosting Lundin's stake to 70% from 51%, the Japanese company said in a statement.

JX, which changed its name from JX Metals in May, sold 51% of its shares in the operator to Lundin in July 2023, with a call option to acquire an additional 19% of the shares within one to five years. Lundin has already exercised that option, according to JX.

For JX, the operation, which will close in July, is part of a reorganization of its asset portfolio. It intends to focus on the advanced materials business, such as sputtering cathodes for semiconductors, while managing the volatility of its resources business.

Asked if JX plans to sell an additional stake in MLCC, a company spokesperson said: "We want to maintain a certain level of interest in copper mines from a raw materials acquisition perspective, but we will also continue to review our portfolio."

Its parent, Eneos, Japan's largest oil refiner, said the deal will have a limited impact on profits for the year ending March 31.

Last year, Eneos said it was preparing to IPO JX shares, although the plans had not yet been finalized.