The oil company Royal Dutch Shell has completed the sale of its shares in the Corrib gas field off the north Mayo coast.
The deal means Shell no longer has any involvement in the operation of the project.
Last year, the Canada Pension Plan Investment Board (CPPIB) agreed a deal to purchase all Shell interests on the Corrib venture, for €1.08 billion.
Gas was first detected off the north west coast in the late 1990s but the project to bring it ashore was mired in controversy and subject to several challenges.
The first gas was processed at a terminal in Bellinaboy in late 2015.
Shell says it is exiting the upstream business in Ireland as a result of the sale.
The company's share of Corrib gas output amounted to the equivalent of around 27,000 barrels of oil a day.
The change in ownership will mean that CPPIB is a new partner in the venture, which is now being operated by Vermillion, another of the companies involved in the project.