Investors are willing to back Rio Tinto’s counter-cyclical bet on Arcadium Lithium but suggested the mining giant may need to pay close to $9 billion to convince shareholders it is more than an opportunistic raider at the bottom of the battery metal price cycle.

Rio and Arcadium on Monday confirmed the approach, which would give Rio control of a vertically integrated, geographically diverse miner that supplies about 5 per cent of the world’s lithium. No terms were disclosed, although the target signalled it is open to hearing Rio’s best offer.