Australia Wednesday approved a massive energy project that will supply natural gas worth tens of billions of dollars to China and India, giving new impetus to its resources boom.

Environment Minister Peter Garrett imposed 28 conditions to protect wildlife but said he saw no reason to block the Gorgon liquefied natural gas (LNG) plant off Western Australia, allowing it to clear the final regulatory hurdle.

The project is a joint venture by Chevron, Shell and ExxonMobil, which has signed a record 41 billion US dollar contract with Chinese giant PetroChina and another worth 21 billion dollars with India's Petronet.

"I've considered it very carefully, I don't believe that there will be unacceptable (environmental) impacts and, as a consequence of that, I have made my decision today," Garrett told reporters.

He said the conditions included measures to protect endangered turtles and other species on nearby Barrow Island and to minimise noise and light emissions.

"It is acceptable for the expansion to go ahead subject to the conditions," he said. "The public can have confidence that the environment of Barrow (Island) will be properly protected."

Garrett said he expected Chevron and the venture's other partners would be "more than willing" to meet the conditions.

"We have had those discussions with the company and it is the case that there is agreement on the basis of the conditions that I've put forward, and I welcome that," he said.

The Gorgon field, thought to hold more than 40 trillion cubic feet of gas, is expected to create thousands of jobs and pump billions of dollars into Australia's economy.

Chevron, majority partner in the project, welcomed Garrett's approval and said a final investment decision would be made in the coming months.

"The Gorgon project is Australia's largest single resource project and is set to deliver significant economic benefits and create around 10,000 indirect and direct jobs during peak construction," said Roy Krzywosinski, the company's Australian managing director.

He said the plant was "globally and nationally significant", with an economic life of at least 40 years, adding it had been sited to minimise the environmental impact.