Mr Maxwell, who joined BHP Billiton in 2004 as President Minerals Exploration, was previously Citigroup's managing director and head of Global Mining Research.
He also has worked for for Anglo American and Rio Tinto in a variety of Exploration and Business Development roles, BHP said in a statement on Tuesday.
Danny Malchuk, currently BHP Billiton Vice President Strategy and Development, Base Metals, will take over from Mr Maxwell as President Minerals Exploration.
Both appointments will be effective from July 1, 2012, with Mr Maxwell based in Sydney, and Mr Malchuk in Singapore.