The company, which had announced in January only that the two Australians were leaving some time in the second half of the year, said it had appointed insiders Ray Gammell as interim group chief executive and Ricky Thirion as interim group financial officer.

The temporary replacements come less than a week after Italy's Alitalia [CAITLA.UL], 49 percent owned by Etihad, filed for special administration for the second time in less than a decade after workers rejected its latest rescue plan.

Alitalia was one of Etihad's key investments as it raced to catch up with fast-growing rivals Emirates [EMIRA.UL] and Qatar Airways by buying into several foreign carriers, including the Italian carrier and Air Berlin, but the Abu Dhabi-owned airline said last week it was not willing to invest further in Alitalia.

Gammell is to continue with a strategic review begun last year though a permanent group CEO is expected to be announced in the "next few weeks", Chairman Mohamed Mubarak Fadhel al-Mazrouei said in a statement.

Gulf airlines have seen growth slow over the past two years against a more challenging economic backdrop. Lower fuel prices dented demand for high-margin premium cabins as Middle East travel budgets tightened, while East to West traffic, an important route for Gulf carriers, diminished after a wave of militant attacks in Europe and Turkey.

Gammell, who joined the Abu Dhabi airline in 2009, currently serves as the group's Chief People & Performance Officer and is a member of the Executive Leadership.

Thirion, who joined the airline in 2007, currently serves as Senior Vice President, Group Treasurer.

An Etihad spokesman said that Thirion had also been appointed on an interim basis without saying when a permanent replacement for Rigney would be made.

(Reporting by Alexander Cornwell; Editing by Louise Heavens, Greg Mahlich)