The countries that were removed from the benchmark were Chile, the Czech Republic, Hungary, Israel, Malaysia, Mexico, Poland, Russia, South Korea and Thailand.

"Along with certain adjustments to the country weightings for government bonds, the changes proposed will facilitate lower transaction costs in the management of the Fund," the ministry said in a statement.

However, the fund may still invest in such bonds as part of Norges Bank's active management, the ministry added.

In 2017, the central bank, which manages the fund, proposed to streamline the fixed-income portfolio by cutting 20 currencies from the benchmark it tracks, leaving only US dollars, euros and British pounds.