The low price of crude oil has led to clear downturns in the Norwegian economy and that pressure should persist, government data show.

"The Norwegian economy has been in a clear, petroleum-driven cyclical downturn for a year," a statement from Statistics Norway said.

Crude oil prices are down more than 50 percent from last year, forcing many energy companies to cut back on spending. In many basins, that means less overall production. Preliminary production figures from the Norwegian Petroleum Directorate, the nation's energy regulator, show an average daily production of around 1.9 million barrels of oil, natural gas liquids and condensate. That's about 2 percent less than July.

The government's statistics office said the decline in investment in the petroleum industry is one of the key factors dragging on the Norwegian economy.

Growth has been slow for most of the year for Norway, with gross domestic product increasing by slightly less than 1 percent for the last four quarters combined.

"We expect a weak tendency for the remainder of the year, and that mainland GDP growth will be 1.3 percent this year," the statistics office said.

Oil prices are expected to remain low for the rest of the year, the office said, with a return to $60 per barrel expected by 2018. Brent crude oil was priced at $48.42 per barrel in early Wednesday trading.

Statistics Norway said the consequence of low oil prices will be seen first in the decline in investments in the petroleum sector.

"We assume that petroleum investment will fall by close to 12 per cent this year and at a gradually slower rate in subsequent years," it said.

NPD boasted of durable interest in the offshore oil and gas sector when 43 companies submitted applications to develop acreage on the Norwegian continental shelf.