BRISBANE - Boosting global economic growth, encouraging private sector investment in infrastructure, and cracking down on multinational companies which avoid tax were the top issues on the G20 agenda, Australian Treasure Joe Hockey said on Saturday.

Hockey, who is chair of the G20 Finance Ministers, made these opening remarks before finance ministers of G20 nations gathered for a special meeting, just before the world leaders summit.

He said the G20 began with the aim of shaping the international agenda to discuss economic and financial issues, and there were three major priorities first and foremost on the agenda.

"We have set an ambitious target of the 2 percent (over the next five years) and we will strive damn hard to achieve that target and there is a positive plan that comes out of that," Hockey said.

In relation to infrastructure, Hockey said it was at the G20 finance ministers meeting that member states decided to fund the massive infrastructure needed around the world over the next few decades through a better partnership with the private sector.

"The global infrastructure initiative, which we will be recommending to the leaders today is a very positive step forward, " he said.

"The infrastructure plan has received widespread support from many multilateral organizations, especially the World Bank."

Hockey said the third top issue on the agenda was stopping large multinational companies from avoiding paying tax through base erosion and profit shifting.

"The Organization for Economic Cooperation and Development ( OECD) has done a terrific job in relation to that. We are only half way through and we will ensure it is dealt with before the end of Turkey's leadership," he said.

Hockey praised the Financial Stability Board, for its effort on focusing on the challenges of financial regulations and focusing on implementing changes, and was confident real outcomes will be achieved over the weekend's discussions.

"We will discuss the state on the global economy at the moment, and it will be a genuine and honest discussion, and I'm very confident that by the end of the weekend we will be able to give a message of hope and aspiration to the world," Hockey said.