Northern Ireland Electricity owner ESB is poised to enter the gas supply market in the province, the Belfast Telegraph can reveal.
The firm plans to offer 'dual fuel' gas and electricity packages to businesses in Northern Ireland.
A subsidiary of the Irish state-owned firm, which completed its purchase of NIE last week, has applied to the Northern Ireland Utility Regulator for a gas supply licence.
Brian Montayne, head of corporate communications at ESB, said: "ESB is proposing to enter into offering 'dual fuel' gas and electricity packages to large, high-end business customers in Northern Ireland.
"These packages are already offered to business customers in the Republic and have been for the last 12 months. In the longer term, these will then be offered to the major small-to-medium sized- enterprises also.
"No decision has been made on whether to eventually expand these packages into the domestic market."
A spokeswoman for the Utility Regulator welcomed the news. "The Utility Regulator welcomes competition in the electricity and gas supply markets and we will continue to work with interested suppliers to provide more choice to energy consumers," she said.
Domestic customers in Northern Ireland currently choose between Phoenix Natural Gas and state-owned Irish company Firmus Energy, controlled by Bord Gais Eireann.
Phoenix, Firmus, Energia and Vayu serve the business community in different locations across Northern Ireland.
ESB completed a £1.2bn deal to buy NIE last week. The agreement finalised plans announced in July for the leading electricity company to take over the northern business.
Under the terms of the deal, NIE will continue to operate as a stand-alone business with its own brand and identity.
Northern Ireland has been fully open to competition since the formation of the Single Electricity Market in November 2007.
In May 2010, Airtricity became the first new company to enter the domestic electricity market.
The Utility Regulator announced in recent weeks that the large industrial and commercial market for gas will open across all areas of Northern Ireland in October 2012.
The markets outside Belfast are 10 locations which include Ballymena, Londonderry, Coleraine and Newry.