The chief executive of BHP Billiton, Marius Kloppers, is set to retire and will be succeeded by Andrew MacKenzie.
Mr Kloppers will retire as chief executive and director on May 10.
The announcement came as BHP Billiton reported today that its profits were down $US5.7 billion in the first half of 2012-13, 43 per cent on a year earlier due to lower commodity prices and the high dollar.
Mr MacKenzie, the 56-year-old head of BHP's non-ferrous business, has three decades of experience in the industry and joined the company in 2008.
Chairman Jac Nasser said Mr Kloppers would leave BHP Billiton "a safer and stronger company".
"Marius was appointed chief executive just prior to the global financial crisis. Despite an exceptionally difficult economic environment during his tenure, Marius and his team have delivered for shareholders, significantly outperforming our peers in terms of total shareholder returns," Mr Nasser said.
"He drove new investments into next generation opportunities including US onshore gas and liquids and created one of the most valuable companies in the world."
Mr Nasser said the change was a result of the company's succession planning process.
"The Board has decided that Andrew is the right person to lead BHP Billiton in a changing global environment," he added.
Mr MacKenzie, who oversees much of the company's portfolio, including key copper mines at Escondida in Chile, said it would be a privilege to lead BHP Billiton.
"I look forward to working closely with Marius during the transition and building on his legacy," he said.
Mr MacKenzie will move to Melbourne with his wife.
Mr Kloppers said it was a difficult decision and that "deciding the right time to retire was never going to be easy". But he added that he believed it was the right time to move on.
The announcement to the market this morning came just a month after Tom Albanese stepped down from mining giant Rio Tinto and was replaced by Sam Walsh as chief executive.