"Crude prices are not satisfactory but... we are not expecting them to rise in the near future... In October, the crude market will be balanced," said NIOC deputy chief Mohsen Qamsari. 

"The market is good, it has a good appetite," he said.  

The head of NIOC's international affairs said he expected China to keep buying its crude despite political pressure from the United States to reduce trade with Tehran. 

"I find it unlikely that the Chinese will avoid Iran's crude unless under heavy political pressure," he told Reuters in an interview. "But they have proven in the past that they won't withdraw even under pressure."  

Western sanctions over Tehran's disputed nuclear program do not prohibit Iranian crude sales. But Iran was deprived of billions of dollars in oil payments from Indian refiners in early 2011 because of payment problems caused by U.S. pressure on India's central bank. 

"As you know our crude sale is not under sanctions so far  and I don't think it will ever happen due to its psychological effect on the market," Qamsari said. 

"I don't want to say sanctions were completely ineffective ... they have slowed down our work, but they haven't halted our activities." 

When asked whether sanctions will have an impact on Iran's crude output, he said : "By preventing foreigners from investing in Iran's energy sector, it will not only harm us but will harm the others as well."

After rallying strongly in early 2011, crude prices on global markets, the main source of income for Tehran, have been pressured in the last few weeks by growing euro zone debt fears, with benchmark Brent crude oil at about $112 a barrel on Wednesday.  

Qamsari said Iran has over 150 billion barrels of oil reserves, compared to estimates by the latest BP Statistical Review of World Energy which pegged its proven reserves at 137 billion barrels at the end of 2010.