OSLO (AFP) - Norway's Government Pension Fund posted a record return of 13.5 percent in the third quarter, thanks to a pick-up in financial markets, the country's central bank said Tuesday.

Oil-rich Norway's Government Pension Fund is one of the world's main sovereign wealth funds and is more commonly referred to as the "oil fund."

It is the biggest investor on European stock markets, and it grew to 2,529 billion kroner (304.3 billion euros, 453.2 billion dollars) at the end of September, from 2,385 billion kroner at the end of the previous quarter.

"The record-high quarterly return can be attributed to a sharp rise in international equity markets and a normalisation of fixed income markets," Norway's central bank said in a statement.

For the last quarter, the return on the fund’s equity portfolio was 17.7 percent and fixed income investments gained 7.2 percent.

The Norwegian government also transferred 49 billion kroner worth of oil revenues into the fund last quarter.

The fund contains nearly all state oil revenues in Norway, one of the world's largest oil and gas exporters.

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