Energy companies ESB and Bord Gáis could be forced to reverse recent price rises if raw material prices continue to fall, the regulator said yesterday.

Speaking at an Oireachtas committee meeting yesterday, Tom Reeves, head of the Commission for Energy Regulation, said if prices continued to decline, his agency would be forced to reconsider the amount it allows the energy incumbents to charge for their services. Crude oil prices were at $59.57 (€46.85) a barrel last night in New York.

Gas prices, as charged by Bord Gáis, went up by 34 per cent earlier this week, while the ESB is set to increase its electricity price by almost 20 per cent at the end of the year - both rises were approved by the regulator, who cited higher raw material costs. Earlier this week, oil fell to a seven-month low.

Mr Reeves declined to say exactly how low prices would have to go before he reassessed the situation, but indicated that a price of about 41 pence per therm of gas at source could trigger such a revision. Two days ago, the price was 51 pence a therm, down from the 61 pence charged in August.

Traditionally, energy prices in the Republic are only reviewed on an annual basis, compared with the UK, where as many 13 different gas price increases have been recorded already this year. When asked by committee members whether this could be changed, Mr Reeves said price cost variation, as the system of ongoing price assessment is known, has been considered on several occasions, though was in the past rejected by industry.

The ESB told the committee that electricity prices for ordinary consumers were not as high as recent reports suggested. Its chairman, Tadhg O'Donoghue, said prices were only 2 per cent above the EU average. Yesterday, representatives from employers' group Ibec and the Consumers' Association of Ireland called on the regulator to evaluate the prices charged by the industry's incumbents more frequently.