Sudan's central bank began circulating a new currency Sunday, less than a week after newly-independent South Sudan did the same.

The new Sudanese pound is similar to the old one but the bills are different colors and have been stripped of symbols representing the south.

The old Sudanese pound has plunged in value this year due to worries the currency would be replaced and because of concerns South Sudan's independence will hurt Sudan's state finances.

South Sudan now controls most of the oil wells that used to provide large streams of revenue for the government in Khartoum.

Officials have said it will take two to three months to replace the estimated 11 billion old pounds circulating in Sudan.

The bank says it not reached an agreement with South Sudan about old Sudanese pounds still circulating there.

Sudan and South Sudan are still at odds over several major issues, including borders and the future of the oil-rich Abyei region.

The disagreements have sparked fears of a new Sudanese conflict. The former northern and southern Sudan fought a 21-year civil war that ended in 2005.