MELBOURNE (BLOOMBERG) - Royal Dutch Shell Plc, which reported its biggest net loss in more than a decade in October and has halted projects in Canada and the Arctic, is reviewing its investments in New Zealand, from gas fields to pipelines.

The Hague-based company made its first investment in the Pacific Island nation in 1911 and is considering options including a full country exit, Mr Rob Jager, chairman of Shell Companies in New Zealand, said on Thursday (Dec 10) during a conference call with reporters.

Shell earlier this year said it would take a US$4.61 billion (S$6.45 billion) charge resulting from the withdrawal from offshore drilling in Alaska and an oil-sands project in Canada.

"Choices have to be made to streamline the global portfolio," Mr Jager said on the call. "Shell is increasingly focusing on large growth opportunities, with deep water and integrated gas as growth priorities."

Oil and gas companies are reviewing portfolios and undertaking the biggest belt-tightening in a generation as prices plunge.

Oil is trading near levels last seen during the global financial crisis as Saudi Arabia leads the Organisation of Petroleum Exporting Countries in maintaining output and defending market share against higher-cost producers, fueling a record supply glut.

Shell's assets in New Zealand include an 84 per cent stake in the Maui gas and condensate field, a half share in the Kapuni gas field and a 48 per cent holding in the Pohokura gas field, Mr Jager said.

A process examining the potential sale of the 307km-long Maui pipeline is continuing and will not be affected by the review, he said.

Shell holds a stake in the pipeline with Todd Petroleum Mining and OMV New Zealand, according to the asset's website.