AIB is extending its branch network for the first time in three years with the expected announcement later this morning that it’s opening two new branches or outlets in Dublin and one in Cork, each with significantly extended operating hours.

The new Dublin branch at Grand Canal Dock, close to a number of large multinational tech businesses, will open for a number of hours on Saturday while the outlet Carrickmines Retail Park, the busiest in the country, will open both weekend days, with the support of the banking union, the IBOA.

The new branches will offer a broad range of personal and business banking services and each will have a complement of five to six staff, but no traditional tellers to offer cash services, they will all be automated.

Yesterday it was revealed that AIB has paid €3.7m to 6,855 business customers who were overcharged on overdraft related fees.

The average refund paid was €543 plus interest, the error was discovered by AIB, who then notified the Central Bank.

The bank commented on the overcharging: "AIB sincerely apologises for this error and any inconvenience caused as a result and the appropriate changes to procedures have been implemented."

It is understood that the bank began repaying this money into customer accounts during last month.