AIB has written to 152 investment clients offering compensation for losses arising out of the trading practices revealed in the recent investigations at the bank.
Many of the clients are understood to be charities.
In its statement last week, the bank said that an investigation by the Irish Financial Services Regulatory Authority found unacceptable deal allocation practices relating to nine transactions, between 1991 and 1993.
At the time, AIB said two specialist trusts had lost out by a total of €174,000 as a result.
The bank said that compensation would be paid and a total of €330,000 would be refunded.
However, RTÉ News has learned that the two trust funds involved had a total of 152 client trusts between them.
The bank has now written to the owners of these, detailing the losses that arose and the compensation it is prepared to pay. It is understood that the typical payment involved is around €2,200.