Under company law, the company's distributable financial reserves must match the combined value of Cork and Shannon airports, which stands at just under 250m, before they can be spun off.

At the end of 2006, according to last week's DAA's annual report, the company's distributable reserves stood at 293m.

Sources have indicated that it is likely that these reserves will top the 250million mark within months once the sale of the DAA's 24% stake in Birmingham Airport for around 312m is completed. The move is the latest in a series of disposals made by the authority in a bid to increase its reserves.

Meanwhile, the company has confirmed that it plans to start making significant progress on the other hurdle facing the split, the drawing up of detailed business plans for each airport this autumn.

This process had been held up by wrangles over Cork Airport's debt and Shannon Airport's restructuring plan but the DAA is confident these issues will be resolved within months. Once it has completed the plans, they will then be submitted to the government for approval.

The company is anticipating considerable resistance from its staff and their unions before it reaches that point and it remains reluctant to place a public date on the separation.

"I have no timeline in mind. It wouldn't be prudent at this stage to have one in mind, " said the DAA's chief executive, Declan Collier.

"I think what we need to do is we need to put together the business plans, submit them to the government, they'll come back and give us their views and we'll see where we go from there."

A spokeswoman for the department of transport said that officials there were in constant contact with the DAA regarding the separation issue but refused to comment further.