Treasurer Scott Morrison has urged the UK and European Union to maintain co-operative and open financial arrangements to avoid lasting implications of Brexit.
Mr Morrison has used a speech to G20 colleagues in Germany to call for collective support as the UK prepares to leave the EU, reconfiguring their trade and investment relationship.
Australia would continue to support and promote global free trade, he said.
"We must recognise that a punitive or restrictive set of new arrangements will have far greater and more lasting implications than the immediate reaction to the poll result itself," he told the G20 conference in Wiesbaden on Thursday.
"Any reduction in financial system efficiency and liquidity within and between the EU and UK would have implications well beyond Europe."
Mr Morrison said the UK had developed into a major trading hub for euro-denominated transactions and restricting the location of euro transactions could impose additional risks and costs for EU and global market participants.
"We must all encourage the relevant parties to explore how the market can continue to operate efficiently and how the UK can continue to support that outcome," he said.
"Negotiators have to recognise the mutual benefits that come from co-operative and open financial arrangements and that the UK will continue to play an important role in the EU financial system."
