The Petroleum Fund's foreign exchange requirements are partly met by the state's direct financial interest in petroleum activities (SDFI) and partly by Norges Bank's purchases in the market.

The Ministry of Finance determines the size of the monthly allocations to the Petroleum Fund. Norges Bank's purchases of foreign exchange are equal to the difference between the allocations and SDFI's estimated foreign exchange revenues. Adjustments are made for any revisions of estimates for the previous month. As a result, the daily purchases may vary somewhat from one month to the next. The daily foreign exchange purchases are determined for a period of one month at a time and are announced on the last business day of the preceding month.

Norges Bank will not purchase foreign exchange in December 2004 as no allocation to the Petroleum Fund will be made for this month. The international equity and fixed income markets are less liquid at the end of the year, and it is therefore inappropriate to transfer capital that must be invested at this time.