AIB is to acquire a 50% stake in Autolease Fleet Management, which trades as NiftiBusiness and Nifti Personal Leasing.
The companies plan to offer low-carbon car leasing options to businesses and personal users.
AIB is providing an initial investment of about €6m and said it will provide more funding to help the joint venture's expansion.
AIB said the deal aligns with its strategy to offer financial solutions to its 2.8 million customers and to grow its green lending, including to customers who want to make the switch to electric and hybrid vehicles.
Today's deal will also provide NiftiBusiness and Nifti Personal Leasing the capacity to grow and to meet demand for electric and hybrid vehicle fleets from businesses of all sizes.
NiftiBusiness and Nifti Personal Leasing have ambitious plans for growth and project that not less than 60% of its overall fleet will be hybrid or fully electric vehicles by 2030.
The deal is subject to approval by the Competition and Consumer Protection Commission.
AIB's Managing Director of Retail Banking Jim O'Keeffe said the bank's ambition is that green and transition lending will account for 70% of its new lending by 2030 as it seeks to support its customers in the transition to a lower carbon future.
"This joint venture is happening at a time when the drive towards sustainability and the need to protect our environment is encouraging many businesses and people to re-evaluate their fleet management and private motoring needs and to demand sustainable and environmentally friendly solutions," he said.
Catherine Guy, CEO of NiftiBusiness and Nifti Personal Leasing, said the deal with AIB will provide the companies with the capacity to grow and meet the increasing demand for fleet management solutions.
"NiftiBusiness and Nifti Personal Leasing have developed the know-how and expertise to respond and this new partnership with AIB strengthens our position, enabling us to cater for all customers, including personal drivers, small and medium enterprises and larger corporations and to facilitate the transition to sustainable electric and hybrid vehicles," she said.