OPEC's second biggest producer Iran is reviewing how much oil it pumps, but no decision has been taken on any changes, Oil Minister Gholamhossein Nozari said on Tuesday. Nozari did not give a reason why it was carrying out the review of production, which hit 4.203 million barrels per day (bpd) in March, the highest level since its 1979 Islamic revolution. "So far we have not decided to decrease output. We are reviewing the issue. The result of this review could lead to an increase or decrease of production," he was quoted as saying by the Oil Ministry's website Shana. "The amount of production and oil supply will be in proportion to the market's demand," he was quoted as saying by Reuters. Iran's semi-official Fars News Agency said on Tuesday Nozari had rejected talk of a cut.