Glencore had raised its offer after its first bid was opposed by key Xstrata shareholders, including Qatar Holding, the Gulf state's sovereign wealth fund.

BBC: Xstrata board backs Glencore merger

While Qatar Holdings, the sovereign wealth fund of Gulf state Qatar, has said it will vote in favour of the merger, it added that it would abstain on a controversial linked vote on whether Xstrata's board members should receive multi-million pound payments to stay with the future merged company.

BBC: Qatar backs Xstrata-Glencore merger