Iran will introduce a new gasoline price tier on Dec. 6, raising the cost of fuel purchased beyond monthly quotas to 50,000 rials (about 4 cents on the Iranian exchange market) per liter, officials said, in a shift that adds a third pricing level to the country's long-running subsidy system.

Under the revised structure, motorists will continue to receive 60 liters per month at the subsidized rate of 15,000 rials. A second tier of 100 liters will remain available for 30,000 rials.