Shares in Anglo American were down 0.5% at 9:00 a.m. London time, while other mining stocks rose.
In a statement, the British miner said board members had unanimously rejected BHP’s “unsolicited, non-binding and highly conditional” proposal.
Anglo American chairman Stuart Chambers dismissed the bid as “opportunistic”.
“The BHP proposal is opportunistic and does not value Anglo American’s prospects, while diluting the relative value upside participation of Anglo American shareholders compared to BHP shareholders,” he said.
BHP did not immediately respond to a CNBC request for comment.
The offer included a requirement that Anglo American spin off its entire shareholding in South Africa-based Anglo American Platinum Limited and Kumba Iron Ore Limited, two entities that together account for a significant portion of the company’s copper production.
Anglo American chairman Stuart Chambers said the proposed restructuring was “highly unattractive, creating significant uncertainty and execution risk borne almost entirely by Anglo American, its shareholders and its other stakeholders.”
Shares in Anglo American Platinum rose more than 2% on the announcement, while Kumba Iron Ore moved 0.9% lower.
Miners are looking to bolster copper supplies in the coming years due to expected shortages and the metal’s key role in the energy transition, with applications in electric vehicles, power grids and wind turbines.
Chambers said Anglo American in its current state was “well positioned” to benefit from this energy transition.
“With copper representing 30% of Anglo American’s total production, and with the benefit of well-sequenced and value-creating growth opportunities in copper and other structurally attractive products, the Board believes that Anglo American shareholders will benefit from what we expect to be significant value appreciation , as the full impact of these trends materializes,” he said.
— CNBC’s Jenni Reid contributed to this article.
