Norges Bank plans to exchange 2 billion crowns ($231.9 million) per day into foreign currency, which will, in turn, be invested abroad by the wealth fund, already the worlds largest with assets of $1.3 trillion.
Economists have said a switch to buying foreign exchange and thus selling crowns may weaken the currency.
Oil prices plunged on Thursday on news that the United States was considering the release of up to 180 million barrels from its strategic petroleum reserve, affecting oil-sensitive currencies like the Norwegian crown.
The euro was up 1.6% at 9.6988 crowns per euro at its highest level since March 18. The dollar rose 1.7% against the Norwegian crown.
