Some are freaked out by Petromin. There is a mis-conception that IOC is beholden to Petromin and therefore Shell, their chosen partner. They conclude IOC will need to bow to Shell. As if the holder of the resource and prime acreage with FID ready willing partners (EWC, Mitsui, 4 OTs) and Gov't approval with an announced contract operator (Engineering firm available and eager to operate for a fee) has no leverage and is attempting to negotiate from a position of strength.
I ran this in the rubbish meter and here's the analysis.
1) IOC is free to negotiate commercially with any acceptable potential partners.
2) PNG is required to pay the same commercial rates as others a for stake above 22.5% in Gulf LNG and other projects.
3) IOC is not pre-destined to swallow a Petromin/Shell low-ball deal.
4) IOC is not negotiating with Petromin/Shell. IOC is possibly negotiating with Shell. Petromin is the manager of PNG's interest, if they are lucky, with the reorganization.

