Back in 1959, the then Taoiseach, Mr Sean Lemass, explained the ideology behind establishing State organisations, some of which had recently started the process of separation from State. He said such entities as the ESB, Telecom Eireann and Aer Rianta had been set up "to meet particular needs and opportunities as they arose, when no other course seemed practicable".

"State-financed industries had been set up only where considerations of national policy had been involved or where projects were beyond the scope of, or unlikely to be undertaken by, the private sector."

There is a certain symmetry in that, 40 years later, the same approach is being adopted by the Minister for Public Enterprise, Ms O'Rourke, as she loosens the semi-State apron strings.

The Government's policy on the liberalisation of State companies has been that any changes in status will be based on practical considerations. Whatever is decided, Ms O'Rourke has said, will be in the interests of the economy, the taxpayers, the company, its employees and its customers.

"Our manifesto for government stated quite clearly that we would look at each semi-State on a one-by-one basis," the Minister said in October. "Each company has its own particular needs and requirements. So it's not simply a question of saying that we are pro-privatisation merely for the sake of it. Some companies are not suitable for privatisation just yet, others are. What matters most is that they become more competitive and react to the many changes taking place in the market place."

State enterprises have an annual turnover of £4.5 billion and employ more than 50,000. As such they are a major player in the economy. In many cases they provide important infra-structural services such as electricity and telecommunications.

Over the years there has been much debate about these companies and whether they should be sold off to private buyers. Some maintain their lack of competition has led to inefficient management and losses within the semi-State sector which taxpayers usually meet.

Others point to the experience in Britain, where the Conservative government under Mrs Thatcher sold off water, electricity and rail companies and then the price of these services increased. In addition, the quality of service was seen to dis-improve as new owners cut corners to maximise profits.

According to a Department of Public Enterprise spokesman, much has been learnt from Britain where, he said, the sale of the former state-owned companies had resembled a "car boot sale".

"Privatisation is not seen as a panacea for all ills and the Minister has a completely open mind on the issue," he said.

While it may not be a car boot sale, there are companies that have, or are likely to have, a "For Sale" sign on their front door. While this development is seen as a response to changing market conditions and a need for more profitability and efficiency in the sectors, much of it has been driven by European directives that allow for a levelling of the industrial playing field.

The process often begins with partial or full deregulation which allows competitors into a once closed market for the first time. Last year the Minister brought forward the deadline for deregulation of the telecommunications industry by 15 months and shortly the company will be floated on the stock exchange. The Government will be minority shareholders.

Other companies preparing for privatisation are Aer Rianta, Aer Lingus, the ESB and the forestry board Coillte.

"It is a challenge to any company when you are moving from a situation where you were running a business according to public policy priorities and then you must change to where your priorities are to succeed in a competitive environment," according to Mr Michael Kelly of the ESB.

The ESB is the State's sole provider of electricity but, by February, 28 per cent of the market will open up to competitors in line with an EU directive introduced in 1996.

In preparing for such a newly competitive marketplace, the ESB, like other semi-states, has had to reorganise. There have been major changes aimed at making the company more efficient. Staff numbers were cut by 2,000 in three years and, in co-operation with the unions, significant changes in work practices were introduced. "We will be competing vigorously for that 28 per cent of the market," said Mr Kelly.

It was announced recently that Aer Lingus will form a strategic alliance with British Airways/American Airlines group. Commentators predict this will be followed by a flotation on the stock market.

Another entity that could be floated is Aer Rianta, which in response to a request from Ms O'Rourke has submitted a report on the company's future strategic direction. One recommendation included the preparation of the company for initial public offering of shares on the stock exchange within the next three years.