Trade Minister Mark Vaile said he would propose a compromise over farm aid in an effort to break the deadlock between the European Union and United States.
He said the extended meeting of the 18-member Cairns Group of agricultural exporters would aim to "inject some energy" into the Doha Round of talks, which collapsed last week.
World Trade Organization chief Pascal Lamy, US Trade Representative Susan Schwab and US Agriculture Secretary Mike Johanns had indicated they would attend, Vaile said. EU Trade Commissioner Peter Mandelson has also been invited.
Mr Vaile's office said Canberra was also "looking at the possibility" of inviting the major Group of Six (G6) trading powers "to meet on the margins."
As well as Australia, the G6 includes the US, EU, Japan, India and Brazil.
"The round's not dead but it really is only hanging by a thread," Mr Vaile told Australian Broadcasting Corporation radio.
Mr Vaile's office confirmed a report in The Australian newspaper that Canberra was proposing a compromise that would involve the US cutting its farm subsidies by a further $5 billion and the EU reducing its tariffs by a further five percent.
Australia hopes that any movement by Brussels and Washington could breathe new life into the free trade negotiations, which opened in the Qatari capital in 2001.
Mr Vaile said a global trade treaty would not be reached by the December 2006 deadline but any progress at the September 20-22 meeting could encourage the US Congress to extend President George W. Bush's fast track authority on international trade deals.
Mr Bush must surrender that authority to Congress in July 2007, potentially making it harder for the US to offer concessions.
The Doha Round was supposed to dismantle worldwide barriers in agricultural and industrial trade and use commerce to give developing countries a boost.
It was meant to yield a trade treaty by the end of 2004 but the target was progressively put back to the end of this year.