The former Rio Tinto chief executive for diamonds and industrial minerals - Andrew Mackenzie is the new appointment at BHP Billiton as group executive and chief executive for its non-ferrous division.%%With this, there has been a shuffle of responsibilities at Rio Tinto. Its Argyle underground diamond project in Australia will now be handled by Rio's head of technology and innovation, Grant Thorne. Its diamond business will fall within the portfolio of Bret Clayton, chief executive of copper at Rio.%%At BHP, Mackenzie will be succeeding Marius Kloppers, who was the former group president of non-ferrous and has now been appointed as chief executive officer. Mackenzie will operate from London and be a member of BHP’s group management committee. Mackenzie has around 30 years working experience in minerals, metals, oil and gas. He will begin his BHP tenure from November 2008.