New Delhi, Jan. 21: Sudan has offered three oil and gas blocks to ONGC Videsh Ltd (OVL), while Indian Oil will double its oil purchases from Nigeria.

The developments are part of the country's efforts to diversify its energy sources.

"Sudan has offered more oil blocks for exploration and asked for Indian companies' expertise to raise production from existing fields," oil minister Dharmendra Pradhan said after meeting Sudan's oil minister Mohamed Zayed Awad on the sidelines of the 4th India-Africa Hydrocarbons Conference here today.

Sudan has also invited Indian firms to set up a coastal refinery to boost fuel supplies to Africa.

OVL already has a 25 per cent stake in Greater Nile Oil Project in Sudan that produces about 50,000 barrels of oil per day (bpd). Sudan has offered Blocks 8, 15 and 24 for exploration and has asked OVL to consider buying a stake in Block 17, which produces 7,000 bpd of oil.

Meanwhile, IOC will nearly double its crude purchase from Nigeria on a term or fixed contract in 2016. "Nigeria has now agreed to increase the term contract from 1.7 million tonnes (mt) per annum to 3 mt in 2016," Pradhan said.

A term contract offers assured supplies at a cheaper price.