Mining giant Rio Tinto has appointed the former boss of toll road owner Transurban, Chris Lynch, as its new chief financial officer.

Mr Lynch will replace Guy Elliot on April 18.

Rio said Mr Lynch will remain on the board and become an executive director and member of the executive committee as chief financial officer-elect on March 1.

He will be awarded a base salary of STG800,000 ($A1.19 million) per year with the opportunity to earn 120 per cent of his base salary.

Rio said Mr Elliott announced his intention to retire in July last year.

The company’s new chief executive Sam Walsh is also streamlining his executive committee by reducing the number of positions reporting to him from 11 to nine.

“The vacant group executive strategy position will not be filled, and strategy will continue to be part of the chief financial officer portfolio,” Mr Walsh said in a statement.

He said Bret Clayton’s role of group executive, business support and operations will be restructured and its responsibilities will transfer to other executive committee members from March 1.

Mr Clayton will stay with the group to oversee the divestment of Pacific Aluminium.

The appointment of Mr Lynch comes a month after Rio Tinto boss Tom Albanese stepped down after the global miner announced it would write down the value of its aluminium assets by $US10bn-$US11bn and Mozambique coal assets by $US3bn.

Rio Tinto subsequently announced a full year net loss for 2012 of almost $US3 billion ($A2.91 billion) and was criticised for its near total dependence on iron ore despite calling itself a diversified resources company.

Doug Ritchie, who led the acquisition and integration of the Rio’s Mozambique coal assets, stepped down from the company last month.