Ireland's leading commercial bank, Allied Irish Banks (AIB), on Wednesday said it recorded a pre-tax loss of 1.687 billion euros (2.33 billion U.S. dollars) for 2013, down 55 percent of loss in the previous year.

In its annual report, AIB said its pre-provision operating profits rose to 445 million euros in 2013, 769 million euros higher than 2012, while its total operating income rose by 34 percent to 1.9 billion euros.

Operating expenses fell by 16 percent to 1.47 billion euros while its staff numbers decreased by 15 percent to 11,431.

AIB chief executive David Duffy described the annual results as continued evidence of the positive impact of the bank's revised strategy on operating performance.

"2013 was a year of steady progress at AIB as we implemented our strategic objectives which saw the bank return to pre-provision, pre-exceptional, operating profit for the year," he said.

"A number of important milestones have been reached and the fundamentals of AIB's performance are now trending more positively both from an operational and economic perspective," he added.

Duffy said AIB remains focused on sustainable growth and returning to profitability during 2014.

"Notwithstanding the ongoing challenges facing the bank, we are more optimistic for the outlook of both the bank and the Irish economy," he said.

AIB is one of the so-called "big four" commercial banks in Ireland. It offers a full range of personal and corporate banking services.