The deal received clearance on Friday from the European Commission's competition directorate. The operation was examined under the simplified merger review procedure. The two companies expect to roll out the new business later this year. The partnership had already received approval from the Irish competition authority. The An Post/Foris JV will offer savings, insurance, credit cards and mortgages.

Sweeney will be the first woman in Ireland to head a financial institution at this level, An Post said.

An Post had contracted to offer limited banking services to AIB customers. The contract is up for renewal within a few weeks.

Discussions between AIB and An Post on the future of that relationship are understood to be ongoing.