Viridian, the ESB's main rival, says its Energia subsidiary has won a contract worth €4.2 million a year to supply gas to the Dublin Airport Authority (DAA).

Under the terms of the contract, Energia will supply three DAA sites in Dublin and Shannon with enough gas to serve 6,500 homes, Viridian said yesterday.

The contract was awarded to the company, Ireland's biggest independent energy supplier, under a competitive tendering process. Energia, a recent entrant to the Irish gas markets, already provides 41 DAA sites with electricity.

"Energia's developing gas business will provide dual fuel options for our customers," said Gary Ryan, the utility's sales and marketing director.

Viridian, which also owns Northern Ireland Electricity and Powerteam Electrical Services, is winning more contracts in the Republic as State-owned bodies seek alternative energy suppliers.

Energia was awarded a contract worth €6.1 million last week to supply electricity to three Government departments, including the department responsible for the future of the ESB.

In May, it was awarded a contract to provide power to 150 Garda stations.

Energia has a 25 per cent market share of the corporate electricity market, on an all-island basis.

It has offices in Dublin, Cork, Galway and Belfast and sources power from Viridian's power station in Huntstown, north Dublin.