Key Points:

Shell is considering selling much of its New Zealand operation after nearly a century here as it moves to concentrate on global oil exploration and retailing in high-growth markets.

Rival fuel companies already here, other global oil giants or financial institutions could be possible buyers.

Shell's businesses under review include 215 service stations, its shareholding in the Marsden Pt oil refinery, a 36 per cent shareholding in construction firm Fulton and Hogan and a 25 per cent holding in the operator of Flybuys.

Its aviation, bitumen, chemicals, commercial fuel, distribution and supply and marine business could also be sold following the review, which should be finished around the middle of the year.

Its New Zealand Refining Company stake alone is worth nearly $300 million. Shell will keep its holding in three gas and oil fields in Taranaki.

Spokeswoman Jackie Maitland said possible sale of the "downstream" businesses - which last year returned profits of $100 million to $150 million - was part of a global review by Shell.

"We're looking at what sort of interest there might be in it. The review is not linked to any financial market turmoil that might be going on. Our business is a very robust business, it's definitely not a fire sale."

Shell has been in New Zealand for 98 years and is the second-biggest petrol retailer, behind BP.

Ms Maitland said that while "business is very profitable here and now", the review would look at the long term.

In countries including the US, big oil firms have backed out of some retail operations in some regions where profit margins are tight in favour of higher-growth developing countries.

Ms Maitland said Shell could sell all or part of its operation as a result of the review.

A Mobil spokesman said it was premature to comment on whether his company would be interested in Shell's assets. "We have a significant place in the market - goodness knows what will come of this Shell review.

"The downstream business generally and the retailing of fuels in particular is a very tough competitive business. It's hard to get a decent return so it's not surprising that people look at that fairly carefully from time to time."

A Caltex spokeswoman said she had not heard of Shell's review and could not comment.

Smaller player Gull said it could be interested. Although having around only 3 per cent of the market here, Gull is the biggest petrol-station chain in Perth.

"Do we have some interest - yes. We'll be looking at what is for sale," said general manager Dave Bodger.

New Zealand Refining's chief financial officer, Dennis Martin, said if Shell sold out he was confident it would be replaced by someone else.

"I don't want to underestimate this but organisations are doing this sort of thing all the time. The only difference here is Shell have told people they're doing it."

Energy Minister Gerry Brownlee received a confidential briefing from Shell on Wednesday afternoon about the review and said he was "comfortable" with it.

"If that were to lead to some sort of divestment I am very confident that the assets they have got and the sites they have got would mean some other international player might well come into the fold.

"I am not concerned that it will lead to a lessening of choice for New Zealand consumers."

- Audrey Young