The Papua New Guinea Government has been told it will earn about 1.2 billion US dollars in revenues over seven years after 2013 if it approves mine extension plans for Ok Tedi copper mine in Western Province.
The National newspaper reports Ok Tedi Mining Ltd saying the money would come from dividends, taxes and royalties.
Ok Tedi's extension plan includes the development of two small underground mines and an open cut mine as well as processing.
The company, which is controlled by a PNG Government authority, says at least 1,500 people and contractors would continue to be employed, although it concedes a key impact to consider would be the disposal of more mine waste.
OK Tedi says that to access the ore by 2014, the development programme will have to start next year.
Mine life extension would produce about 100,000 tonnes of copper and 350,000 ounces of gold per year.
The newspaper reports Ok Tedi sees the extension as an opportunity to provide continued benefits to national, provincial and local economies, but at a reduced level.