(Reuters) – The euro and the dollar jumped against the Norwegian crown as oil prices fell and after Norway’s central bank said it would buy foreign currency for its sovereign wealth fund in April. 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 world’s 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 re…