Conglomerate Essar is looking to buy a stake of at least 5% in Spanish energy giant Repsol, business daily Expansion reported on Thursday.
The operation would cost the company, which is already involved in the energy sector, 1.3 billion euros (1.7 billion dollars) at current market prices, it said.
Repsol declined to comment on the report.
Essar is studying whether to buy the shares on the open market, from Spanish savings banks La Caixa and Catalunya Caixa, or from Repsol's main shareholder, Spanish builder Sacyr Vallehermoso which holds a 20% stake in the energy firm.
Last month Repsol approved the sale of 40% of its Brazilian affiliate to Sinopec, China's largest oil group, for 7.1 billion dollars.