The airline said the purchase reflected its desire to forge a commercial partnership with the Irish national carrier.
Etihad Airways believes a possible partnership could produce significant commercial benefits for both airlines.
Etihad Airways operates 10 flights a week from Abu Dhabi to Dublin and has carried more than 750,000 passengers between the two capitals since it began flying the route in July, 2007.
The airline has a premium lounge at Dublin Airport, an engineering maintenance facility and has conducted recruitment drives across the country. It also recently renewed its sponsorship of the GAA's Hurling All Ireland Senior Championship, signing a five-year deal.
Etihad Airways has strategic code-share partnerships with 34 airlines around the world.
