Once the large merger between Santos and Oil Search occurs the former will own 42.5%, more than operator ExxonMobil and will most likely farm down a stake.
Marape, whose government holds 12.4% already, would like that extra 10%, The Australian reports.
A Santos spokesperson confirmed to Energy News that chief Kevin Gallagher is in Port Moresby.
Exxon holds 33.2% and is seen as the most likely candidate to take the share. France's Total, operator of the Papua LNG project, is another candidate. The government holds 22.5% of that project.
The government has already distributed 7% of its share of PNG LNG to local governments.
Petroleum minister Kerenga Kua believes the 42.5% holding would be "onerous" for Santos, but the best option would be for it to offer the government first right of refusal. How Port Moresby would pay for it was not answered.
Debt, or a loan from Santos are possibilities. Santos is not in the habit of loaning project partners money; the only recent deal was a $13.5 million loan to Queensland CSG player Comet Ridge for it to take Australia Pacific LNG's share of the Mahalo fields.
In return Santos has the option to take a larger share of the same project and if it declines Comet will need to pay the money back.
The government also has its own right of refusal over the merger itself given Oil Search is headquartered in PNG.
The main concern, apart from equity in the LNG plants, is that the deal to create a "regional champion" would also see Oil Search leave the local securities exchange.
Marape has been clear the deal must create value for PNG
"Oil Search Limited is a prominent PNG company whose activities comprise a significant percentage of PNG's GDP and provides the livelihood to thousands of Papua New Guineans both directly and indirectly. Any proposed merger must satisfy the national interest test," Marape said in early August.
"We do not wish for the largest oil and gas company operating in our country to simply be a branch office of a foreign company."
There will be two court hearings in PNG to decide on the merger before it goes before Oil Search shareholders, who must agree at a rate of 75%.
Santos shareholders will own 61.5% of the new company, down from an original 63% but higher than analyst speculation that a 40%-60% offer was needed to get the deal over the line.
