AIB has agreed to sell AIB Jerseytrust Limited to the Capita Group for £12.5m (€14.3m) in cash.
The deal is subject to approval by the Jersey Financial Services Commission and the Jersey Competition Regulatory Authority.
The sale is part of AIB's programme of asset sales aimed at reducing its size and improving its financial position.
Earlier this week, AIB announced the sale of its AIB International Financial Services business for €33m, also to Capita, as part of the sell-off strategy.
AIB also announced plans to de-list its shares from the New York Stock Exchange, because of the recent increase in the State's stake in the bank to 99.8% and in order to save money and administrative efforts.
