Norges Bank reported that the fund gained 613 billion kroner ($103.4 billion) on investments. That's the best result since Norway established the sovereign wealth fund in 1996 to invest surplus oil revenue abroad and avoid overheating its domestic economy.

The Government Pension Fund-Global, commonly referred to as the oil fund, grew 16 percent during 2009 to 2.64 trillion kroner ($445.3 billion) from 2.28 trillion kroner in 2008, when the fund posted its worst result ever - a loss of 23 percent. A strong krone reduced the fund's market value, Norges Bank said.

Yngve Slyngstad, the fund's senior manager, attributed this year's result to improvements in international markets, in particular "the fixed income markets that stopped working during the financial crisis." "Developments in 2009 must, in the same way as 2008, to a large extent be viewed in light of the financial crisis.

The fund's long-term management strategy ensured that we got through this period in a good way," said Slyngstad.

At the end of 2009, the fund's average holding in international equity markets was 1 percent and 1.8 percent in European markets. Slyngstad has said that Norway's oil fund is probably the largest equity investor in Europe.