But in her first public speech since taking office last month, Aaslaug Haga said companies could do more to reduce their carbon footprints.

"We need a private sector which is conscious about its responsibility," said Haga, who said she wants to prioritise investment in renewable energy.

"Climate change is our time's biggest challenge," she said, adding that a greener industry could provide competitive advantages for Norwegian firms.

Haga spoke at a presentation of a new study showing that Nordic firms were not taking enough action in the fight against global warming, even though they were relatively more aware of the issues than many of their peers elsewhere in the world.

"Norway has a big responsibility in international climate cooperation because we have large petroleum production and are a rich country -- exactly because of the petroleum," she said.

Fast growing consumption of fossil fuels has been seen as a leading cause of rising global temperatures and has triggered the creation of markets for emissions of heat-trapping gasses.

Norway is the world's fifth biggest oil exporter and Western Europe's top gas exporter.

The study from the Carbon Disclosure Project (CPD) said Nordic corporations have largely failed in converting awareness into action.

"... Corporations need to take vital steps towards concrete emission reducing actions," it said.

Twenty-five Norwegian companies, all listed on the Oslo Stock Exchange, were asked to participate in the study, out of which 16 companies answered.

Oil and gas producers Statoil and Norsk Hydro since merged into StatoilHydro, received the highest score for "emission disclosure" among Norway's carbon-intensive firms. Telephone group Telenor was a leader in the low-carbon sector.