Hayward, who has been Glencore Xstrata's interim chairman since Sir John Bond was ousted by shareholders last year, is also chief executive of London-listed oil company Genel Energy Plc.

His confirmation as chairman of one of the world's largest mining groups completes Hayward's return to the top of the corporate world after he was forced out of BP following the catastrophic 2010 Deepwater Horizon oil spill.

Hayward is expected to eventually step down as chief executive of Genel, the oil and gas explorer he has invested in alongside British-born financier Nat Rothschild, a source close to the matter said.

Genel, which focuses on producing oil in the autonomous Iraqi region of Kurdistan, declined to comment on whether Hayward would leave.

"Tony Hayward is and continues to be CEO of Genel Energy and will continue to do both roles, as he has done successfully for the past 12 months,” a Genel spokesman said in a statement.

One media report on Wednesday said Hayward would leave Genel after a successor has been found and a handover period allowed to take place, while another said Hayward was expected to leave within a year.

"If he does end up leaving we would see this as a negative for Genel. Nevertheless the fundamentals of our Genel investment case... remain intact," said Arden Partners analyst Daniel Slater.

After leaving BP, Hayward co-founded Vallares Plc with Rothschild and became chief executive of Genel Energy Plc in 2011 after the merger of Vallares and Turkey's Genel Energy International Limited.

In his permanent role at Glencore Xstrata, Hayward could help the company with new acquisitions in the oil sector.

"Oil seems to be a growing arm of the Glencore business and if they want to push and expand a bit more Tony's expertise can certainly help with that," Investec analyst Marc Elliott said.

(Additional reporting by Paul Sandle; Editing by Erica Billingham)

By Silvia Antonioli and Karolin Schaps

Stocks treated in this article : Glencore Xstrata PLC, BP plc