"I would feel over the next number of years there would be no difficulty in doubling our size in Ireland, " chief executive Fiacra Nagle told the Sunday Tribune. O'Briens already has about 100 franchised outlets here. Nagle said the company has identified a number of locations it feels are ripe for expansion.

Limerick, Cork, Galway and Waterford are among the key targets. Nagle said O'Briens also sees plenty of room for growth in Northern Ireland, where it will open five stores this year. It will open "between 15 and 20" new outlets in the Republic over the same period.

Not all the new O'Briens Sandwich Bars will be high street retail units. Nagle said the company wanted to take advantage of other retail locations such as petrol station forecourts. It will also look introducing more outlets along the lines of its "motorway stop-off" just outside Portlaoise off the M7 motorway. "What we're introducing is a more flexible format, " said Nagle.

At the same time O'Briens will continue with its expansion outside Ireland . In the past year it has opened its first two stores in China and has awarded a master franchise to an operator in Australia, which recently opened two sandwich bars in Sydney.