BSc (Hons) (Environmental Engineering), MEng (Environmental Engineering)
Preston was appointed Group executive, Technology & Innovation in 2009. He joined the Group in 1991 at Kennecott Utah Copper's Bingham Canyon mine as vice president, Technical Services. In 1995 he became vice president and general manager of the Boron Operations in California and was chief executive of Rio Tinto Borax from 1999 to 2003. Preston then became chief executive of the Energy group and in 2007, upon a management reorganisation, he also assumed responsibility for the Industrial Minerals group.
Preston was a director of Cloud Peak Energy Inc. from 2008 to 2011, director of Rössing Uranium Limited from 2004 to 2009, and director of the World Coal Institute between 2003 and 2009, serving as chairman from 2006 to 2008. Since 2006 he has been a board member of Resources for the Future, an environmental and natural resources policymaking body.