TEHRAN, Iran (AP) — Iran's atomic agency says it will begin exporting less heavy water because of an oversupply in the international market.

State TV quotes agency spokesman Behrouz Kamalvandi as saying on Tuesday that Iran will export some 20 tons of the material annually from now on.

That's much less that the 70 tons of heavy water that the country exported to the United States, Russia and Oman since last year's nuclear agreement went into effect in January.

A recent report by the U.N. nuclear watchdog said that Iran had exceeded its heavy water limit by 100 kilograms (about 220 pounds) over the 130 metric tons allowed. Heavy water is used to cool reactors that produce large amounts of plutonium.