The government has reduced the windfall tax on diesel and aviation turbine fuel (ATF) exports from October 1, in a move that brings relief to domestic refiners.

The Special Additional Excise Duty on diesel has been cut to Rs 16 per litre from Rs 20, while the levy on ATF has been reduced to Rs 10.5 per litre from Rs 15. The tax on petrol remains unchanged at Rs 0.5 per litre.

The windfall tax is reviewed every fortnight based on global crude oil prices. It was first introduced on March 27 amid tensions in West Asia that sent oil prices soaring.

Lower global crude prices in recent weeks have reduced the super-normal profits of refiners, prompting the government to trim the levies.

Analysts say the cut could marginally improve the margins of refiners such as Reliance Industries and ONGC, which export petroleum products.

The government reviews the windfall tax every fortnight, adjusting it in line with international crude prices. Officials said the levy will continue as long as global oil markets remain volatile, keeping refiners' windfall gains in check.