AIB says it has already booked the losses from its 49.99% stake in a Bulgarian bank which it sold in May for €100,000 although it originally paid €216m in 2008.
A spokeswoman said the value of its stake was written down to zero over several years, and finally written off completely in 2010.
She confirmed that the purchase price of €100,000 reported in Bulgaria was accurate but she added that it would not affect this year's accounts.
AIB said in May that it had agreed to sell the stake, but did not disclose the price paid.
A statement on BACB's website said the stake had been bought by Clever Synergies Investment Fund (CSIF), which is owned by businesswoman Tsvetelina Borislavova.
BACB is a publicly-listed bank based in Sofia in Bulgaria, and is focused on small to medium sized enterprises.
Media reports in Bulgaria suggest the buyer was also likely to take on BACB's outstanding debt.
AIB wants decision on interest payment
AIB has asked the High Court to determine whether it should pay interest due on bonds which are the subject of a legal challenge by an investment firm.
Aurelius Capital is challenging AIB's decision to impose losses on some of its subordinated, or junior, bondholders.
AIB said that if the challenge were successful, interest on these bonds would be due on June 25. AIB wants the court to declare that its obligation to pay the interest is suspended, pending the outcome of the Aurelius case.
The hearing requested by AIB will take place on Friday. AIB says it will pay the amount due to the agent for the bonds, Citibank, but will instruct it to hold the money until the court's decision.
