Former Minerals Council boss Brendan Pearson has been appointed Australia's ambassador to the Organisation for Economic Cooperation and Development in Paris.
Mr Pearson was most recently a senior trade adviser in Prime Minister Scott Morrison's office and has held a number of roles in the Department of Foreign Affairs and Trade.
He has also worked with global coal giant Peabody Energy.
The appointment comes at a time the OECD is considering a ban - backed by the US, UK and Canada - on financing for coal-fired power generation which does not use carbon capture or sequestration technology.
Richie Merzian, the Australia Institute's climate and energy program director, queried the appointment, calling it another backward step for Australia's climate credentials.
"The Australian government already has a reputation as a lobbyist for the fossil fuel industry and the appointment of a fossil fuel lobbyist to represent Australia at the OECD in Paris does little more than cement this growing global perception," he told AAP.
Former finance minister Mathias Cormann took on the role of OECD secretary-general in June.
The body provides advice, analysis and research on a range of issues including trade, health, employment, agriculture, aid, energy, education, the digital economy and environment policy.
Alexander Robson has served in the ambassadorial role for Australia since 2019.
Australian Associated Press