Key facts

Market value - 10.5bn euros 2001 profit estimate - 400m euros 31,000 employees founded - 1966

With a market value of 10.5bn euros on Wednesday, it became Ireland's largest company last week before its shares dropped on the news of the alleged fraud.

It stole the top-spot from the pharmaceutical firm Elan whose shares lost three-quarters of their value in a week after Enron-inspired fears over its accounting practices.

AIB stock was tipped for growth at the start of the year, after the Standard and Poor's credit rating agency raised its negative outlook to stable in December.

Humble beginnings

Formed in 1966, it was born out of the merger of three Irish banks and has become a high street name in the UK and the Republic of Ireland.

Michael Buckley: the man at the helm

It has since moved into the US and Poland and now employs more than 31,000 people worldwide in more than 1,000 offices.

Trading under the name First Trust bank, it employs almost 3,000 people in 70 outlets in Northern Ireland.

The bank's initial estimates forecast reporting net profits of 997m euros in 2001, excluding a loss of about 596m euros because of the alleged fraud.

As well as its retail division, it also operates in global capital markets offering foreign exchange, corporate banking, asset management and stock broking services.

Expanding abroad

It is in the foreign exchange division in the US that the fraud is suspected to have occurred.

AIB started investing in the US in the 1980s, and formed Allfirst in 1999 out of the merger of First Maryland Bancorp in which AIB first invested in 1983, and Dauphin Deposit Corporation, acquired in July 1997.

Allfirst and AIB's American outlets now employ about 6,000 people and Allfirst is one of the top 50 US banks.

It has almost 300 branches in Maryland, Pennsylvania, Washington DC, Virginia and Delaware.

AIB has also made a substantial investment in Poland, having a majority share in one of Poland's top five banks by assets.

It acquired stakes in Wielkopolski Bank Kredytowy and Bank Zachodni before merging the two.

Under the guidance of group chief executive Michael Buckley, it is an Irish registered company with shares quoted on the Dublin and London stock exchanges.