Sanctions-hit Iran on Saturday called for OPEC to hold an extraordinary meeting to rein in output going over its agreed total quota because oil prices have dipped to a \"critical level\" under $100 a barrel. \"We have asked the secretary general to set up an extraordinary meeting as prices have become irrational,\" Iranian Oil Minister Rostam Qasemi was quoted as saying on his ministry\'s official news website Shana. He stressed that the last Organisation of Petroleum Exporting Countries meeting, on June 14, had decided the cartel\'s overall quota would be 30 million barrels but \"members\' production has reached 33 million barrels a day.\" OPEC had agreed that \"when the prices go below $100 a barrel, they have reached a critical level,\" and therefore an extraordinary meeting was needed before the next scheduled OPEC meeting in December, he said. Iran is suffering under tightened Western sanctions aimed at severely restricting its all-important oil exports. Those sanctions will get tougher from Sunday, when an EU oil embargo -- which will also block most insurance for tankers carrying Iranian oil anywhere in the world -- comes into full effect. Tehran had been banking on the sanctions to cause oil prices to spike higher, off-setting their impact. But quota-busting production by OPEC members Saudi Arabia and Kuwait, coupled with the European Union\'s debt woes and slowing growth in China have tilted the global oil supply-and-demand balance out of its favour. Iran, along with Venezuela, an OPEC member that is also strongly anti-US, are pushing within OPEC for production to be cut to boost prices. The price of Brent crude, a reference on the market, slipped from a four-year high of $128 a barrel in early March to less than $100 a barrel. On Friday, Brent North Sea oil for August delivery was selling for $97.80 a barrel -- a big jump over previous days\' trading but still under the $100-a-barrel target set by OPEC. The price issue has exacerbated tensions in OPEC between top producer Saudi Arabia and Iran, the second-biggest producer. The two countries are also vying to grab the seat of the cartel\'s secretary-general after the current holder of the post, Abdullah El-Badri of Libya, steps down this year. Ecuador and Iraq have also put forward candidates for the job, which is to be decided in OPEC\'s December meeting.