Viridian, the Northern Ireland power group, has reported an 11.5 per cent rise in pre-tax profits to £86.6 million sterling (€124.55 million) from £77.7 million for the year ended March 31st.

It said further sales growth in Northern Ireland and contributions from its non core businesses would help drive profits in the coming year.

But Dr Patrick Haren, chief executive, said the Government was moving "too slowly" in opening up the electricity market.

The rules and conditions for entering the Republic's market were not being made clear, he added.

Viridian's annual turnover rose to £512.2 million from £50 0.4 million, with operating profits increasing by 15.4 per cent to £86.9 million from £75.3 million.

Earnings per share were up to 54.6p from 14.3p, although when diluted, because of the UK's windfall tax on utilities, earnings per share only rose from 44.3p to 53.8p.

The company's pre-tax profit figure was slightly above market forecasts, according to analysts, and the company's shares were up almost 3 per cent in London yesterday.

Significant storm damage to Viridian's network in Northern Ireland over the Christmas period had a major impact on the figures. Because almost a quarter of its customers were left without supply, Viridian's subsidiary in Northern Ireland - Northern Ireland Electricity - decided to pay £9 million in goodwill payments to customers.

While this reduced profits significantly, Viridian also benefited by £7.5 million from the re-capitalisation of costs relating to its inter-connector with Scotland.

The company's prices to customers in Northern Ireland have been frozen for the past two years and Dr Haren said this continued to affect profitability.

The chairman, Mr Philip Rogerson, said Viridian was pursuing several growth opportunities in the Republic, including combined heat and power plants and other generating stations.