An Iranian state energy firm has announced a major discovery of around 34 billion barrels in associated oil reserves at an offshore gas field in the Gulf, official media reported on Monday.
A huge oil layer has been found in coastal waters near the southern port city of Bushehr, said Ali Vakili, managing director of Pars Oil and Gas Co, quoted by Iran's state-run television website.
"This is one of the biggest layers of oil in the country and it is under the reservoir of the Ferdowsi offshore gas field. We are currently drilling a well to accurately assess the volume of oil," he said.
Vakili did not specify if the amount was already factored in to figures announced by Oil Minister Masoud Mirkazemi on October 11.
OPEC member Iran's proven oil reserves have risen by nine percent to 150.31 billion barrels, partly driven by new discoveries, the minister told a news conference last month.
The announcement came a week after neighbouring Iraq said it had overtaken Iran in terms of oil reserves, catapulting it to third place worldwide behind Saudi Arabia and Venezuela.
Iran is under mounting international pressure over its controversial nuclear programme and Western firms have either pulled out or delayed their commitments in the vital energy sector after new sanctions were imposed on Tehran.