Woodside Petroleum asserted its decision that a floating platform is the best development concept for the Greater Sunrise liquefied natural gas project in the Timor Sea citing economics reasons.

Woodside managing director Don Voelte said, "Evaluation results demonstrate that Floating LNG has robust economics, maximising total revenue to Australia and Timor-Leste and maximising the return to Sunrise Joint Venture."

Voelte said that East Timor would earn about $15 billion over the life of the project from its 18% share of the gas, while Australia stood to earn about $22 billion from its 82% share.

Development of Sunrise through floating LNG is estimated to cost more than $US11 billion. Woodside said the price is $US5 billion cheaper than building an onshore plant in East Timor.

East Timor Prime Minister Xanana Gusmao has publicly criticised the Woodside Petroleum and its partners in the Sunrise joint venture for trying to steal the country's natural resources.

The East Timorese government said that an onshore liquefied natural gas terminal in East Timor is the only to develop gas from the Greater Sunrise field, arguing that floating LNG is untested, risky technology.

"A mere 150 kilometers off the coast of Timor Leste, onshore development is much more prudent, risk adverse, commercially viable and economically transparent," said East Timor in a statement.

In April, Woodside Petroleum and its joint venture partners "unanimously selected" floating LNG as the preferred development concept for Greater Sunrise gas fields.

Australia and East Timor completed a treaty in 2007 for the administration of the Greater Sunrise gas field, which straddles a boundary between Australian waters and an area jointly managed by the two countries. They agreed to share royalties.

The Greater Sunrise gas field can hold an approximate of 240 million barrels of light oil and 154 billion cubic metres of natural gas.