LONDON - Activist investor Bluebell Capital Partners has told Glencore's board it opposes a $22.5-billion all-share takeover bid for Teck Resources, considering the transaction a "value destructive" deal.

In a letter dated April 12 seen by Reuters, London-Based Bluebell said the deal would combine two businesses with questionable synergies, adding it would be a mistake to make a massive acquisition in steelmaking coal prior to demerging the coal business.

Glencore has offered Teck's shareholders to receive 24% of the combined metals group and up to $8.2-billion in cash for those who may not want exposure to thermal coal, which is the most polluting fossil fuel.

Glencore declined to comment.

The unsolicited takeover offer for the Canadian copper-and-zinc miner would involve combining and spinning off the thermal and steel-making coal businesses of both companies, while rebranding the copper and other base metals businesses as GlenTeck.

Teck rejected the sweetened offer on Thursday, saying it is still not in the best interest of the company, pushing yet again for a proposed restructuring.

"The revised offer announced on April 11, not only fails to address any of our concerns but in our view makes the whole transaction alarmingly illogical," said Bluebell's partners Giuseppe Bivona and Marco Taricco.

Bluebell, which has not disclosed the size of its shareholding, started an activist campaign at Glencore in 2021, urging it to separate its thermal coal business, which up until now the miner had said it wanted to deplete by mid-2040s rather than selling or spinning out.

Bluebell argued that exposure to coal was significantly weighing on the company's valuation, while pressure on financial institutions to reduce their lending to the fossil fuel industry posed a risk to the company's future access to capital.

"It is admittedly difficult to propose a deal that satisfies both the shareholders of the target company and those of the buyer and it is equally difficult to propose a deal that will displease them all: Glencore's board of directors seems to have succeeded in this remarkable task," said Bluebell.

Glencore has always said that if the majority of shareholders wants them to spin out coal, whose price has rocketed in the past two years, the company will do so.