Customers who have switched to gas in Londonderry are paying more than a third less in bills than those in Belfast, Firmus Energy has claimed.
The company made the claim during a presentation to Derry City Council to update the Regional Services Committee on the progress of the new gas line into the city.
To date over 300km of pipeline have been laid by the company, with hundreds of homes and some of Derry's largest public and private sector stakeholders now connected.
Neil Holland, Firmus' sales and marketing representative, told the committee: "Firmus locked in prices from January 2006 to January 2009. There were price hikes we didn't pass on. The prices are cheaper than with Phoenix in Belfast, with customers in Derry now benefiting from 37% cheaper bills."
SDLP councillor Helen Quigley asked, however, by what margin prices are likely to rise when the fixed price structure ends in January next year.
Mr Holland said oil had gone up from $62 a barrel this time last year to $122 dollars now.
"Any increase in price would go through the regulatory process and customers would be notified about the increase before they actually pay. All we can do is keep an eye on the gas prices," he said.