Exxon Mobil's $US19 billion liquid natural gas project in Papua New Guinea is now 90 per cent complete and on track to deliver first gas in the second half of 2014.
The LNG project is the largest ever commercial development in PNG.
A statement issued by Esso Highlands, the project operator, says that with 19,000 people currently working on the project significant progress is being made.
It says gas is now flowing down the 700 kilometre pipeline from the highlands to the LNG plant near Port Moresby.
Project executive Decie Autin says the project costs remain unchanged from last year at $19 billion dollars, despite difficult conditions in the country.
She says first gas is expected on schedule in the second half of next year.
Paul Baker, executive director of PNG's Institute of National Affairs, told Radio Australia's Pacific Beat the announcement is significant.
"It's a big watershed for PNG. It's the largest project that the country has developed," Mr Barker said.
"There were many doubters who thought it would be a step too far and to bring it off really is a major achievement for the country and for the companies that are participating.
Several landowner groups in the Highlands say they have been left out of discussions on sharing the project's benefits. They have also accused the PNG Government of being slow to deal with their concerns.
Mr Barker says the country can expect to start seeing increased revenue from the LNG project in 2017.
He says it is important that landowners and politicians see the benefits in terms of investments and capacity building in PNG, and "not in terms of just quick bucks that will be consumed".
"The government needs to really concentrate on investing in the roads and the infrastructure, to enable the broader economic activities to occur, to enable opportunities to be going into the other sectors that actually generate the jobs."