Quoted distribution group DCC was a thwarted suitor of Irish National Petroleum, according to documents released under the Freedom of Information Act. Mr Jim Flavin, chief executive of the company, wrote last September to the Minister for Public Enterprise, Ms O'Rourke, expressing disappointment at not being asked to bid for the State-owned refining company.

The letter from Mr Flavin was not released by the Department, but is listed on a scheduled of withheld documents as a "Representation from DCC on their not being included in the INPC search process". The Department confirmed that DCC indicated it would have been interested in the firm, which was sold to Tosco Corporation, a US company, in July. Mr Flavin was not available for comment on Friday.

The US oil company paid $100 million (€113 million) for the operating assets of INPC, which include the Whitegate Refinery in Cork. Tosco has since been acquired by Phillips Petroleum, a large US oil company.

The timing of Mr Flavin's letter is surprising given that Tosco had been in talks with the Government since August last year after reaching agreement in principle to buy the assets of the business.

The purchase of INPC would have been well within the reach of DCC, which is quoted on the Dublin and London stock exchanges and has a market capitalisation of around €850 million (£670 million) and very little debt.

Energy is the second most important of its four operating areas in terms of turnover and profit. It has targeted the sector for expansion and made a number of acquisitions in the last year, including buying an oil distribution business in Scotland and northern England from BP for €15 million. DCC operates in Ireland under the Emo brand for petrol and oil and uses the Flogas brand for gas in Ireland and the UK.

The company now claims to be the largest independent importer and distributor of oil and gas in Ireland and the UK.

A move into oil refining would represent a shift in strategy for the group. One of the reasons that the Government was keen to exit the refining business was the requirement for ongoing investment to comply with European environmental directives. However, the assets of INPC could have been attractive to DCC if it had obtained the same terms as Tosco.

Under the sale agreement, the Government retains INPC's debts of €135 million. It has also retained liability for any environmental issues relating to the firm's period under State ownership. In addition, some €10 million has been put aside by the Government for an employee share ownership scheme which will purchase shares in Phillips Petroleum on behalf of the staff.

The sale was tied to the ending of the mandatory regime under which oil companies operating in Ireland had to buy 20 per cent of their needs from INPC in order to ensure the viability of the Whitegate refinery. The regime was the equivalent to a levy of six cents per litre of petrol.