The Irish government is the second largest shareholder in Aer Lingus with a 25 percent stake, which it kept when the airline was privatised to ensure it would continue to serve Irish cities.

British Airways owner International Airlines Group has had two bids for Aer Lingus rejected in recent weeks and is widely expected to make a third bid, although it has declined to comment on its plans.

"Should such an offer be made, we will take great care and exercise great caution in examining the pros and cons to Ireland of any such offer," Transport Minister Paschal Donohoe told parliament.

In addition to the value of the bid, the government will examine how a merger would affect connectivity and competition for air routes out of Ireland, including from regional airports, Donohoe said.

A key issue for the Irish government in the past has been maintaining Aer Lingus's frequent flights to London's Heathrow Airport. But Donohoe said that while Heathrow remains an important hub, "other hub options are becoming available."

No formal offer has been made for to Aer Lingus shareholders, Donohoe said.

(Reporting by Conor Humphries; Editing by Larry King)