Iranian oil production has dropped to about 500,000 barrles a day, well below the original government target of about 3 million barrels daily earlier this year, an oil ministry official said yesterday.

The official, who asked not to be named, said no oil has been exported to Western countries since May 17. He did not identify those nations.

But Iran has stopped oil shipments to the United States and European nations that have imposed economic sanctions as a result of the American hostage crisis.

Oil minister Ali Akbar Moinfar said recently oil production had fallen to slightly less than 2 million barrels daily, about evently split between domestic and export sales.

The government, however, has counted on producing about 3 million barrels a day to meet economic target this year. Iran relies on oil money for about 60 percent of government revenue.

Oil contributes about $23 billion a year to the Iranian treasury, based on average production of 3 million barrels a day. The production cut will seriously reduce that revenue.

In recent weeks, the government has been keeping oil production figures confidential except for official pronouncements by cabinet ministers such as Moinfar.

Iran has posted a price of $35.37 per 42-gallon barrel for its oil.