South African state-owned asset manager the Public Investment Corporation (PIC) said on Wednesday that it would require a “meaningful revision” of BHP Group’s bid for rival miner Anglo American.

Anglo rebuffed BHP’s initial $39-billion all-share proposal made on April 25, dismissing it as opportunistic.

It subsequently rejected a revised offer of $43-billion saying the world’s largest listed miner “continues to significantly undervalue” the company and that its difficult to execute.