The value of the Norwegian government's direct investments in oil and natural gas fields is now estimated at 1,584 billion Norwegian crowns ($162 billion), an increase of 540 billion since 2020, the country's industry ministry said on June 27.

The estimated value of the assets known as SDFI, was based on a study by consultancy Rystad Energy.

"A significant rise in the price of oil and gas, among other things as a result of the war in Ukraine, explains much of the increase," the ministry said.

Still, the long-term forecasts for gas prices were largely unchanged since 2020, it added.

While Norway's petroleum production is operated by commercial oil firms, the state maximises its own revenue by holding minority stakes in dozens of fields, known as SDFI.

The government thus earns revenue from the oil and gas in three different ways: taxes on companies' profits, dividend payments from state-controlled Equinor and direct profits from the SDFI stakes.