Norwegian giant Statoil posted a rise in profits during the third quarter as lower tax and operating expenses helped offset a slight dip in revenue, while it also warned it expected output to fall in 2013.

The company posted a net profit of Nkr14.5 billion ($2.5 billion) for the three months to 30 September, up from a profit of Nkr9.9 billion during the third quarter of 2011.

The rise in profits came despite revenues slipping from Nkr166.4 billion during the third quarter of 2011 to Nkr165.3 billion this year.

Statoil attributed the dip in revenue to lower prices and a fall in liquids volumes, however this was partly offset by a rise in gas prices and the volume of gas sold.

During the quarter, the average liquids price was $99.9 per barrel, down 7% from the $107.5 per barrel achieved during the same quarter last year.

Gas prices during the third quarter of 2012 averaged Nkr2.16 per cubic metre, up 10% on the Nkr1.97 averaged during the same period a year ago.

The fall in revenue was partly offset however by a 1% reduction in total operating expenses, to Nkr125.8 billion, and a 9% drop in income tax, from Nkr32.3 billion to Nkr29.4 billion.

Statoil noted that its income taxes during the third quarter were equivalent to an effective tax rate of 66.9%, compared to 76.6% in the third quarter of 2011.

It attributed the decrease to impairments, with lower than average tax rates, in the third quarter of 2011, and high deferred taxes in the third quarter of 2011 compared to deferred tax income in the third quarter of this year.

Output during the quarter was also up with company’s equity production averaging about 1.81 million barrels of oil equivalent per day, up from 1.76 million boepd a year earlier.

An 18% rise in equity gas production, to 753,000 boepd, offset a 6% decline in equity liquids production to 1.06 million boepd.

“Statoil delivered solid financial results in the quarter. By ramping up new fields, we have grown production year to date by 10% compared to the same period last year, and 8% compared to the 2011 average,” Statoil chief executive Helge Lund said.

“This is in line with our plans. Our operational performance is solid and we progressed an extensive maintenance programme according to plan.”

He added the company was on track to meet its full year production guidance, despite an expected 30,000 boepd drop in output during the fourth quarter due to planned maintenance work on the Norwegian Continental Shelf.

The company also warned that output was likely to drop below 2012 levels next year following its divestment in a number of producing assets on the Norwegian Continental Shelf earlier this week to German company Wintershall.

It added that growth form its US onshore gas production was also expected to be about 22 million boepd lower that it had earlier assumed as a result of lower gas prices.

Despite this, the company said it was on track for an average growth of 2% to 3% from 2012 to 2016 and for equity production to rise above 2.5 million boepd in 2020 as new projects come online from 2014.