Glencore has come under criticism from some shareholders for being the last company in the blue-chip FTSE-100 index with an all-male board.

A group of British public-sector pension funds, for example, has criticised both Glencore and Hayward, the former BP boss who on May 8 was appointed as permanent chairman after serving a year as interim chairman, for their failure to set targets for female representation on its board.

"Glencore values and promotes diversity across the company," Hayward said when opening Glencore's third annual general meeting since its listing in 2011.

(Reporting by Silvia Antonioli; Editing by Keiron Henderson and Pravin Char)