Shell is considering selling its assets, as part of a review of its interests in New Zealand.

It's announced the review today, citing a need to become a simpler, more profitable company as the reason.

But the multi-national oil and gas company says its set of assets will continue to be part of New Zealand's energy's mix, whether it owns and operates them or not.

The review will get underway as soon as next week.

"How long the process will take after that is really quite unpredictable because to fully inform each of the options will take time and will have lots of challenges," country chairman of Shell New Zealand Rob Jager said.

He acknowledged there are a range of options facing the company.

"Anywhere from business as usual, so continuing to manage the business the way we are today, to potentially a full country exit and all the options in between."

Jager said Shell is conscious of the uncertainty this creates for staff, and is hoping to make the review process quick.