The central bank in October announced the mechanism for setting the exchange rate on a daily basis through a new body of bankers and exchange bureaus.
The move, which allowed for a sharp devaluation of the local currency, was part of a package of measures designed to tackle an economic crisis.
But the Sudan Media Centre, citing a source in the body that sets the currency rate, said on Wednesday the decision to suspend it was taken by the central bank governor after he met the body to review its work.
The website gave no further details and officials from the central bank could not immediately be reached for a comment.
Sudan's economy has been struggling since the south seceded in 2011, taking with it three-quarters of oil output and depriving Khartoum of a crucial source of foreign currency.
(Reporting by Khalid Abdelaziz; Eriting by Sami Aboudi; Editing by Alison Williams)
