Norway's $1tn sovereign wealth fund could become a "world-class responsible investor" in private equity, by leading with strong governance and transparency standards in the sector — if it finally gets the green light to enter it.

The fund, which is managed by Norges Bank Investment Management, is restricted to stocks, bonds, real estate and private companies that are actively seeking a public listing. The world's largest holder of publicly-listed equities has so far been unable to invest in companies that are not traded on public markets, though over the last five years has been looking into how it could expand its investment horizons.