ACT Treasurer Andrew Barr said David Nicol would take up the position as Under Treasurer next month.

"Mr Nicol, who is an economist by training, has extensive experience in designing and managing budget and financial policy frameworks. He has spent the last four years playing a key role in coordinating the Commonwealth Government’s budget processes in his capacity as Manager of the Budget Policy and Coordination Division in the Department of Finance and Deregulation," he said in a statement.

"Mr Nicol has also managed the Commonwealth Government’s strategic review program and has significant experience in the design and delivery of major policy initiatives in areas including social welfare and income support, government service delivery, industry, labour market and education policy. His extensive career includes working as the policy officer for the HIH Royal Commission in 2003, as a member of the secretariat to the National Commission of Audit in 1996 and as a budget officer in a state government."

He will take over from Dan Stewart, who was acting in the position for five months since the Government restructured the ACT public service.

Megan Smithies, who had been the Under Treasurer for five years before that, was moved to take over the new Commerce and Works Directorate.