Shell New Zealand is poised to cement the sale of $400 million of gas and oil assets within days, and Todd Energy is tipped as one of the two buyers lined up.

After announcing a $133 million asset sale to Swift Energy on Tuesday, Shell Petroleum managing director Lloyd Taylor said two buyers had been found for the onshore oil and gas fields of McKee, Mangahewa, Kaimiro and Ngatoro.

"All we need to do now is dot the i's and cross the t's and then we'll make an announcement on the sale before Christmas," Dr Taylor said.

He stressed that the two buyers were each negotiating for separate assets and that "both buyers will get what they want".

He also said his company was on track to meet Commerce Commission requirements which stipulate that Shell must sell selected assets by early next year.

Macquarie Equities senior analyst Arthur Lim said it was "highly likely" that Todd Energy would be one of the two buyers.

Meanwhile, Shell Todd Oil Services has outlined plans for the Pohokura gas field in Taranaki, a project which could involve investment of up to $900 million.

Developing New Zealand's second-largest natural gas discovery will involve installing up to three offshore production platforms, constructing a production station at Motunui, laying new pipelines and a possible expansion of Port Taranaki.