The Productivity Commission is reviewing mining project approval delays.

The year-long review is designed to look at how to streamline regulation across Australia's resources sector.

The commission will examine examples of best-practice regulation that reduces unnecessary costs for business, while maintaining oversight.

Treasurer Josh Frydenberg says improving the efficiency of environmental approvals is extremely important.

“All Australians have a stake in the resources sector and the benefits must be shared fairly,” Mr Frydenberg said in a joint statement with Resources Minister Matt Canavan and Assistant Minister to the Prime Minister Ben Morton.

“It has become harder than ever to get new resources projects off the ground, restricting the sector's future expansion and costing jobs right across Australia.”

The probe will look at Adani's Carmichael coal mine, which took nine years to get final approval, among other case studies.

It will be undertaken alongside a statutory review of the national environmental protection law due to kick off in October.

“The aim is to ensure that resources projects are transparently and efficiently assessed, while upholding robust environmental standards,” the ministers said.