Though trade levels increased during the third quarter, the number of jobs opened in the Norwegian oil and gas sector continues to decline, national data show.

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

Statistics Norway said the trade surplus for September was $1.9 billion, the second lowest level since March 2003.

In a snapshot of labor figures, the data-mining body oil and gas said employment prospects were dwindling.

"The number of job vacancies in the production of oil and gas decreased by half from the third quarter of 2014 to the third quarter of 2015," the agency said.

By comparison, manufacturing employment was down 39 percent from last year, though overall trade was up 25 percent year-on-year. Across the board, there were 51,800 job openings in the Norwegian economy during the third quarter, a 5.3 percent decline from last year.

Statistics Norway said there's been a decrease in the number of jobs available in the oil and gas sector in every quarter since fourth quarter 2012.

The government's statistics office attributed some of the decline in employment to an aging workforce, suggesting the sector is not attracting younger workers. In 2013, more than 70 percent of the oil and gas workforce was below 50 years of age, a figure that dropped nearly 2 percent the following year.

Low crude oil prices are damaging economies like Norway's that depend heavily on oil and natural gas for revenue. Norge Bank, the country's central bank, said in September that a weakened value of its currency, the krone, could make exports more attractive, though the overall economy is expected to falter and unemployment is projected to rise.