India's HPCL may buy 2.8 million tonnes of crude from Iran in 2012/13, a little less than the three million tonnes of a year earlier, its chairman said on Wednesday, citing business reasons rather than the impact of sanctions on Tehran.

Iran crude buyers in Asia, its biggest market, are under pressure from Washington to reduce oil imports as the United States and its allies seek to force Tehran to halt its nuclear programme. New U.S. sanctions make it tough for Asian importers to pay for Iran's oil.

If HPCL imports less crude, it would be because of refinery economics, Chairman S. Roy Choudry said on Wednesday, and not because of any payment problems.

Iran is India's second-largest oil supplier after Saudi Arabia. Iran's biggest Indian customer, Mangalore Refinery and Petrochemicals, said on Tuesday it might buy less oil from Iran this fiscal year, citing refinery shutdowns.

India relies on Iran for about 12 percent of its oil needs or around 350,000-400,000 barrels per day (bpd). New Delhi is one of Tehran's biggest customers.

Neighbouring Pakistan, which imported in total 346,400 bpd in 2009, is not buying oil from Iran, its oil minister Asim Hussain said at an event in New Delhi on Wednesday.

Indian refiners have struggled to find ways to pay Iran in the past 13 months after a clearing mechanism was scrapped in December 2010 and refiners have sought alternative supplies, but so far none have announced any cuts in Iran imports as a result.

Payments are currently being routed through Turkey's Halkbank but this too is looking vulnerable after fresh sanctions from both sides of the Atlantic.

On Monday, the European Union banned imports of oil from Iran and imposed a number of other economic sanctions, joining the United States in new measures it took on December 31.-Reuters