Mining giant BHP Group on Thursday said it had made an all-share takeover offer for rival Anglo American, valuing the smaller company at £31.1 billion ($38.9 billion).

Anglo American shares leapt at the market open and were 12% higher at 9 a.m. in London.

The company confirmed it had received an “unsolicited, non-binding and highly conditional combination proposal,” which it said it was reviewing with advisers.

Australia-based BHP, the biggest listed miner according to Companies Market Cap, said that the deal would deliver 0.7097 BHP shares per Anglo American share to Anglo American’s ordinary shareholders.

A combination of the firms would form a juggernaut in copper mining and the world’s largest player in the space which would supply 10% of global output, according to a Reuters analysis. Anglo American has a huge copper operation based in South America and a production target for the metal of 730,000 to 790,000 tons in 2024. This compares with a copper output aim between 1.7 million and 1.9 million for BHP over the same period.

Mining firms are seeking to shore up copper supplies over the years ahead due to projected shortages and the metal’s key role in the energy transition, with uses in electric vehicles, power grids and wind turbines.

The mining industry has experienced an uptick in merger and acquisition activity over the last four years as companies position themselves for changing demand patterns.

BHP in 2022 merged its dual-floated business into a single legal entity with a primary listing in Australia.

Markets had closed before the announcement Thursday morning.

The proposal would entail divestments by Anglo American to its shareholders of its stakes in South Africa-based Anglo American Platinum Limited and Kumba Iron Ore Limited.

“The combination would bring together the strengths of BHP and Anglo American in an optimal structure. Anglo American would bring its assets and long-term growth potential. BHP would bring its higher margin cash generative assets and growth projects along with its larger free cash flows and stronger balance sheet,” BHP Group said.