International energy company Equinor has been told to hand over more information on its environmental plan for drilling in the Great Australian Bight.

The National Offshore Petroleum Safety and Environmental Management Authority has given Equinor another 60 days to submit the extra information after the authority's assessment team found gaps in the plan.

"The request for more information is a standard step in the assessment process. Equinor will submit the additional information within the timeframe outlined by NOPSEMA to progress the assessment process," the company said in a statement.