Government will offer oil exploration blocks to foreign and domestic companies on Thursday under the fourth round of its New Exploration Licensing Policy, government officials said.

Global oil majors did not bid in the previous NELP rounds but the discovery of a large gas field with estimated reserves of 14.5 trillion cubic feet by Reliance Industries last year is expected to attract foreign firms, they said.

"We certainly expect a better response this year. Apart from Reliance, there have been several other discoveries in India," an oil ministry official said.

Oil Minister Ram Naik will formally announce the blocks on offer on Thursday.

So far, 70 exploration blocks, including 16 onland, 30 in shallow water and 24 in deep-sea regions, have been awarded to Indian and smaller foreign companies since 1999.

These companies have spent $1.5 billion in oil exploration and are expected to double their investment in the next few years, officials say.

India is inviting foreign firms in oil exploration and is scouting for equity oil abroad as it depends on imports for 70 per cent of the crude oil requirement of its 17 refineries that can process 2.3 million barrels per day.