Australian Environment Minister Peter Garrett said Friday he will make a decision in the next week on whether to grant environmental approval to the giant Gorgon gas project offshore of Western Australia.

If Garrett gives the project the green light, that would be the last of the regulatory approvals, clearing the way for the Gorgon partners to make a final investment decision, possibly as soon as next month.

Garrett said many of the environmental issues around Gorgon have already been covered by the Western Australia state government, which approved the project earlier this month.

"But I want to be absolutely sure that all of the matters in front of me have been thoroughly considered, and that if there are going to be conditions that apply to this project that they are conditions that ensure that matters of national environmental significance are properly protected," Garrett told reporters.

The Gorgon field, which has potential reserves of more than 40 trillion cubic feet of gas, is located off the coast of Western Australia. It is being developed by ExxonMobil Corp. (XOM), Chevron Corp. (CVX) and Royal Dutch Shell PLC. (RDSB). Shell and Exxon each have a 25% stake in the Gorgon project, while Chevron has a 50% stake and will act as operator.

If it goes ahead, the A$50 billion Gorgon project would be the largest-ever resources project in Australia, dwarfing the A$12 billion Pluto LNG project being developed by Woodside Petroleum Ltd. (WPL.AU).

Exxon has struck two deals over Gorgon LNG so far this month, including a 20-year deal with PetroChina Co. (PTR), the listed unit of China National Petroleum Corp., to buy 2.25 million metric tons of LNG a year, and a 20-year agreement to sell 1.5 million tons to Petronet LNG Ltd. (532522.BY), India's largest LNG importer.

-By Rachel Pannett, Dow Jones Newswires; 61-2-6208-0901; rachel.pannett@dowjones.com