Norway's sovereign wealth fund grew 14.9 per cent and achieved a 12.7 per cent return on its investments in the second quarter, the central bank said, indicating a pick-up in financial markets.

The fund's value grew to 2.38 trillion kroner (€277 billion), up from 2.07 trillion kroner at the end of March.

The central bank also said the fund's return on investment stood at 12.7 per cent over the same period, it's best-ever quarterly performance.

"Economic developments showed clear signs of stabilising in the second quarter and the uncertainty around the financial sector decreased. Liquidity is beginning to return to a number of fixed income markets," said Yngve Slyngstad, the head of the central bank's investment division.

The Government Pension Fund contains nearly all state revenues from the oil industry in Norway, one of the world's largest oil and gas exporters.

It was set up to help finance its generous welfare state system once the wells run dry.

In the period from April to June, state oil revenues brought in 40 billion kroner to the fund, down from 44 billion in the previous quarter.

The fund currently has stakes in around 8,000 companies worldwide.

At the end of the second quarter, it held the equivalent of one per cent of the world's total stock market capitalisation and 1.7 per cent in Europe.