Mining big Anglo American on Friday rejected a takeover bid from rival BHP Group, saying the supply “considerably undervalues” the corporate and its future prospects.

Australia-based BHP on Thursday stated it had made an all-share takeover supply which valued the smaller firm at £31.1 billion ($38.9 billion). The takeover would have created the world’s largest mining firm, in keeping with a Reuters evaluation.

Shares of Anglo American had been buying and selling down 0.5% at 9:00 a.m. London time, whereas different mining shares rose.

In an announcement, the British miner stated that board members had unanimously rejected BHP’s “unsolicited, non-binding and extremely conditional” proposal.

Anglo American’s Chairman Stuart Chambers dismissed the bid as “opportunistic.”

“The BHP proposal is opportunistic and fails to worth Anglo American’s prospects, whereas considerably diluting the relative worth upside participation of Anglo American’s shareholders relative to BHP’s shareholders,” he stated.

BHP didn’t instantly reply to a CNBC request for remark.

The supply had included a requirement for Anglo American to demerge its complete shareholdings in South Africa-based Anglo American Platinum Restricted and Kumba Iron Ore Restricted, two entities which collectively account for a sizeable proportion of the corporate’s copper manufacturing.

Anglo American Chairman Stuart Chambers stated the proposed restructure was “extremely unattractive, creating substantial uncertainty and execution danger borne nearly completely by Anglo American, its shareholders and its different stakeholders.”

Shares of Anglo American Platinum rose greater than 2% on the announcement, whereas Kumba Iron Ore moved 0.9% decrease.

Mining corporations are in search of to shore up copper provides over time forward attributable to projected shortages and the metallic’s key function within the power transition, with makes use of in electrical autos, energy grids and wind generators.

Chambers stated that, in its present state, Anglo American was “nicely positioned” to learn from that power transition.

“With copper representing 30% of Anglo American’s whole manufacturing, and with the advantage of well-sequenced and value-accretive development choices in copper and different structurally enticing merchandise, the Board believes that Anglo American’s shareholders stand to learn from what we anticipate to be vital worth appreciation as the total affect of these traits materialises,” he stated.