Xstrata has rejected an informal cash and share takeover approach from Brazilian mining group Vale pitched at just under £40 a share or $76bn (£38.9bn) for its entire equity.

Xstrata and Glencore, the Swiss commodities trader that owns 35 per cent of the Anglo-Swiss mining group, dismissed the offer and are holding out for a price equivalent to about £45 a share, according to people close to the deal.