The increase comes despite a downgrade in mid-term profit goal by parent firm Eneos last month.

JX said accumulated operating profit in the three years to March 2023 would be 250 billion yen ($2.3 billion), against its last year's outlook of 170 billion yen.

Copper prices have risen more than 30% this year to hit a record peak this month as some of the world's largest economies showed signs of recovery from the impact of COVID-19, boosting expectations of increased demand.

JX lifted its price assumption regarding the industrial metal for the financial year to March 2022, to 340 cents per pound from its previous estimate of 270 cents, and for next year to 320 cents, from 270 cents.

The stronger copper prices contributed 100 billion yen to the profit upgrade, offsetting a negative impact of 40 billion yen from the pandemic, JX said.

The pandemic will continue to slow copper output at its Caserones mine in Chile this year because of labour curbs, but annual production will reach 165,000 tonnes in 2022, the company said.

"We are looking to invest in tantalum and titanium mines," the firm's President Seiichi Murayama told a news conference.

"As massive investment is required to invest in base metals mines, we will prioritize rare metals for now."

In February, JX bought the stakes in Caserones owned by its partners Mitsui Mining and Smelting and Mitsui & Co.

Asked if JX would look for new partners, Murayama said the company was always reviewing its asset portfolio.

"I can't guarantee that we'll hold a 100% stake forever," he said.

($1=109.8400 yen)

(Reporting by Yuka Obayashi; Editing by Clarence Fernandez)