Finavera, the natural energy company, has found a gas reservoir that it claims could turn the Republic into a net gas exporter.

The firm said yesterday that technical tests on its Lough Allen natural gas field in the northwest had shown a potential gas resource of 9.4 trillion cubic feet of gas, or 1.5 billion barrels of oil equivalent, the standard industry measure.

Finavera claims the field could meet the Republic's gas demand, at current levels, for the next 25 years. Reserves of the level suggested by the initial tests would be about nine times larger than those held in the Corrib field off Co Mayo or the Seven Heads field off the coast of Co Cork.

"The Lough Allen natural gas field has the potential to change the energy dynamic of Ireland and the UK," said Tom Davitt, Finavera's chief executive.

He pointed out that the Republic currently imports almost 90 per cent of its gas requirements through pipelines connected to the UK, which is also a net gas importer.

Finavera argues that the recent gas dispute between Russia and Ukraine highlighted the vulnerability of gas supply to European countries.

"The EU has recently urged Ireland to set up a strategic gas reserve as it is one of only three states that does not store gas to provide for emergencies," the company said yesterday.

Mr Davitt said: "There is no doubt that the Irish economy would be in a vulnerable position if there was a serious disruption in supply. The answer to a large part of our security of supply problem could be in the northwest of Ireland."

Finavera owns 100 per cent of the 1,630 sq km field in the Lough Allen basin, which traverses Sligo, Leitrim, Cavan and Fermanagh.

The company is in the process of raising €10 million through Goodbody Corporate Finance so that it can carry out a seismic analysis and further development work on the field. This money should be in place over coming weeks.

The fundraising is part of Finavera's preparations for an initial public offering on Iex and Aim, which Mr Davitt said should happen this year. He declined to say how much of the company was being offered in exchange for the initial €10 million.

The initial analysis on Lough Allen was completed in conjunction with Schlumberger, the oilfield services provider. The study involved examining existing data from previous exploration on the field.

Mr Davitt said the drilling technology needed to extract gas economically is already used routinely and successfully in similar stagings in the US and Europe. It has not, however, been used in the Republic.

"The application of this technology has turned previously uneconomic reservoirs into commercial gas fields," he said.

Finavera was set up in 2003 by four individuals, including Mr Davitt, who have a background in exploration disciplines.

At the start of 2005, the company split its assets into the gas venture and Finavera Renewables, which focuses on renewable energy.