BHP's proposed takeover of Anglo American has been knocked back.

The $60 billion deal would have been one of the largest transactions in the sector, but Anglo American chairman Stuart Chambers says the proposal was “opportunistic”.

On Thursday, Anglo American confirmed receiving an all-scrip offer from BHP, though details of the offer price were not disclosed. 

About 24 hours later, Anglo American announced it would not accept the bid. 

“The BHP proposal is opportunistic and fails to value Anglo American's prospects, while significantly diluting the relative value upside participation of Anglo American's shareholders relative to BHP's shareholders,” Mr Chambers said.

“The proposed structure is also highly unattractive, creating substantial uncertainty and execution risk borne almost entirely by Anglo American, its shareholders and its other stakeholders.

“Anglo American has defined clear strategic priorities - of operational excellence, portfolio, and growth - to deliver full value potential and is entirely focused on that delivery.”

Anglo American operates significant steel-making coal and manganese mines in Australia and is a leading global producer of copper, with additional mining operations spread across Brazil, China, Peru, and South Africa. 

A merger with BHP would see the formation of the world’s largest copper miner. 

Anglo American’s market value is a fraction of BHP's, leading some to suggest that Anglo American shareholders will push for a better price from BHP after its $60 billion bid was rejected.

Reports say investors are confident BHP would be willing to pay more. Recent financial reports from Anglo American revealed a substantial drop in profits, prompting a reduction in its dividend payments. 

The company has also recently reduced its copper production targets and announced significant job cuts across its South African platinum operations, reflecting broader challenges within its operational portfolio.

Anglo American investors will grill the board at its annual general meeting in London on Tuesday (8pm AEST).