Mumbai: Essar group company Essar Energy Holdings Ltd, a unit of Essar Global, has won an offshore oil block in Nigeria with reserves of up to 80 million barrels.

Essar Energy bagged a shallow water offshore exploration block 226 in the African country, industry sources.

Nigeria had offered 45 exploration blocks in its latest licensing round, to which no Indian company except Essar had responded.

Of the total 45 blocks, 11 were in deep water offshore, 10 shallow water on the continental shelf, 13 onshore in the Niger Delta and 11 in inland basins.

ONGC-Mittal Energy Ltd, the joint venture of state-run Oil and Natural Gas Corp and NRI steel tycoon L N Mittal, had preferential bidding rights over one block, but chose to stay away.

Indian Oil Corp-Oil India Ltd combine, which earlier planned to submit a bid, also stayed away, the sources said, adding a total of 16 companies bid in the round.

ONGC-Mittal had won preferential rights after promising to invest two billion dollar in the country''s infrastructure.

OMEL was given right of first refusal on block 250 in return for a pledge to carry out a feasibility study into a new railroad, the sources said.

Mittal, meanwhile, lost a bid for taking over Nigeria''s biggest oil refinery.

Mittal offered lesser than the 561-million-dollar winning bid by a consortium of three Nigerian indigenous companies for acquiring 51 per cent of government stake in Port Harcourt refinery, industry sources said.

The winning Blue Star consortium comprises Zenon Oil, Dangote Oil and Gas and Transnational Corp, which belong to close associates of outgoing President Olusegun Obasanjo.

Blue Star emerged winner of the refinery in an open bid conducted yesterday by the Nigerian privatisation agency - Bureau of Public Enterprises in Abuja.

Two other bidders, local fuel marketer Oando and the Sahara/Refinee PetroPlus, were disqualified for not providing bank drafts to cover 50 per cent of their bid amount.

The sources said Mittal had originally planned to bid for the 2,10,000 barrels per day Port Harcourt refinery with Hindustan Petroleum Corp Ltd (HPCL) but in the end went alone.