AIB and Aviva today completed their deal to give the insurance giant a 75 per cent share of Ark Life.
The parties say their five-year renewable deal is a joint venture, while the European Commission who gave the go-ahead for the deal on Friday called it an acquisition by Aviva.
It added that the deal did "not significantly impede effective competition in the (European Economic Area) or any substantial part of it".
AIB will get a cash payment of up to €204 million and retain a 24 per cent interest in Ark Life through its bankassurance unit.
Hibernian Life & Pensions, Aviva's Irish subsidiary, will take over Ark Life, consolidating its position as the third-largest player in the Republic's long-term savings market. Hibernian is now third and Ark fourth.
The combined entity will have a market share of around 19 per cent, compared with Bank of Ireland at 24 per cent and Irish Life at 25 per cent, Aviva executive director Philip Scott said.