Iranian Central Bank governor Valiollah Seif said the secondary currency market would help "minor importers" buy their dollars, and emphasized that the price of the dollar would be set according to market supply and demand, Press TV has reported.
The move will allow some 20% of the dollars from the export of non-oil products (also excluding steel, petrochemical and minerals) to be sold in the secondary currency market at rates mutually agreed upon by exporters and importers.
President Trump's decision to pull out of the Iran nuclear deal and reimpose sanctions against Tehran is also believed to have played a role in the rial's ongoing depreciation.
Iran has sought to reduce dependence on the dollar via a package of measures, including increased trade using the euro and other currencies.