Under the terms of the treaty, East Timor will receive 90% of royalties from all oil and gas projects located within the Joint Petroleum Development Area that includes the Bayu-Undan project and 20% of the larger Sunrise gas field.

Santos managing director John Ellice-Flint said ratification of the treaty should pave the way for commercialisation of the Bayu-Undan field.

"Following the project ramp-up, LNG production net to Santos would be over 3 million barrels of oil equivalent (mmboe) per annum. Approximately 50 mmboe of probable gas reserves would be moved to proven reserves," Ellice-Flint said.

The Bayu-Undan project is operated by ConocoPhillips (64.14%). The other stakeholders include Santos (11.83%), AGIP (12.32%) and INPEX (11.71%).

Woodside also welcomed ratification of the Timor Sea Treaty and signing of the International Unitisation Agreement for Greater Sunrise.

"These agreements set the legal and fiscal framework under which Woodside and its joint venture participants will seek to develop the Greater Sunrise gas fields and the Kuda-Tasi and Jahal oil discoveries, located in the Timor Sea between Australia and Timor-Leste," said Woodside's gas business unit director, David Maxwell.

The Sunrise Joint Venture partners are Woodside (33.44%) - operator, ConocoPhillips (30%), Shell (26.56%) and Osaka Gas (10%).