The ESB will lose almost £30 million (€38 million) in projected revenue this year as a result of a direction issued yesterday. The ruling on charges states it should charge its rivals significantly less than it originally sought for the use of its infrastructure to distribute power.

This direction was made by the Commission for Electricity Regulation (CER) on the eve of a 28 per cent liberalisation of the market. ESB will be allowed to generate revenue of £479.9 million in 2000 through leasing its infrastructure.

This is £30 million lower than the figure it included in its submission to the CER in October 1999.

A breakdown of the allowed charges show projected distribution revenue of £357.5 million for ESB in 2000, 6 per cent lower than the October submission. Revenues accruing from use of the transmission system are projected to be £104.4 million, £27 million higher than the October submission.

But when the costs incurred for running the transmission system are accounted for, allowed revenue is down 10 per cent from the October submission.

The price system means electricity suppliers will pay on average 2.56p per unit for electricity carried along the ESB's transmission and distribution network. It is understood ESB had proposed a price above 3p.

These prices charged for using the ESB's infrastructure are crucial to enable power companies to access the ESB transmission and distribution system and offer cheaper electricity.

Yesterday's ruling ends months of wrangling over access and cost. Last night, ESB management studied the document and would not comment on the detail. A CER spokesman said the charges were competitive when compared with UK prices and demonstrated a well-regulated electricity industry.

But the Labour Party spokesman on public enterprise, Mr Emmet Stagg, strongly criticised the Minister for Public Enterprise, Ms O'Rourke, for a "foolhardy, headlong rush to introduce full liberalisation" which will damage the industry.

Energia, Viridian's independent energy supply company, welcomed the new market for electricity, which begins today.

The company announced yesterday it had signed up Gallahers tobacco and CRH as customers and would supply electricity from tomorrow using the Northern Ireland inter-connector.

From today, 28 per cent of the corporate electricity market has been opened to competition.

By 2002 this will be 40 per cent, and full liberalisation should take place by 2005.