An interim examiner has been appointed to Aer Arann by the High Court.
The company said a loss of €6m sustained during the volcanic ash crisis, as well as losses of €6m in 2008 and 2009, have forced it to seek examinership.
Michael McAteer of Grant Thornton has been given the task of ensuring the implementation of a restructuring plan.
His appointment is not expected to interfere with the day-to-day running of the business and the airline will continue to operate as normal during the interim examinership.
No flights have been cancelled and the airline said that flights can still be booked on its website.
The case will be heard in full in the High Court on 8 September by Mrs Justice Maureen Clarke.
In a statement the airline said: 'Following the High Court hearing on 8th September Aer Arann expects to remain in examinership for an initial period of up to 70 days.
'During that time the company will benefit from the protection of the Court from its creditors so that it can re-organise and re-structure the business.
'Aer Arann and the Examiner will also use the time to negotiate with potential investors and a number of parties have expressed their interest in the airline.'
The airline, which was set up in 1970, currently employs 320 people.
It operates several routes in Ireland and also serves a number of cities in the UK and France.
Aer Lingus has said that its 'franchise agreement with Aer Arann remains in place'.
In a statement it added: 'Aer Lingus Regional flights, operated by Aer Arann, will continue to operate normally and customers who hold bookings on these flights need not be concerned as there will be no disruption in service.'