The bidders understood to be still in the running for the network of service stations, depots and terminals include Tesco, Tedcastle, DCC/Musgrave, Irving Oil of Canada, Petrogas and Ion Equity, which bought Shell's petrol stations when they were put up for sale.

Around 30 groups are believed to have made formal expressions of interest in buying the Statoil business.

On the block are 236 stations, of which 69 are company owned.

The Norwegian company has also put on the market 16 distribution depots and oil terminals in Dublin, Galway, Cork and Derry.

The Statoil sale follows the sale for some 180 million last year of Shell's service station network to Topaz, a group backed by Ion Equity.

The Statoil network was not initially seen as being as attractive as the Shell portfolio, as fewer of the properties are held in freehold title.

Statoil is Ireland's largest petrol retailer, with 20% of the market.

It reported turnover in 2004 of 1.07bn, and a pre-tax loss of 2.7m. Its operating profit of 1.09m was recorded after an exceptional charge of 6.5m for a severance package.

Merrill Lynch is handling the sale of the Statoil assets.

The deadline for the second round of bidding was postponed from 8 May.