Confidential documents seen by RTE News have highlighted concerns over the impact of the break-up of Aer Rianta on the company's €484m debt.
Last week independent Senator Joe O'Toole asked that the Attorney General examine the implications of the break-up on the debt position of the company.
If Aer Rianta is split, its banks are likely to demand higher repayments as in legal and actual terms it will be a different company.
On June 30, Aer Rianta chief executive Margaret Sweeney wrote to the Assistant Secretary at the Department of Transport to highlight these concerns.
In a letter seen by RTE News, Ms Sweeney quoted advice to the company from solicitors Arthur Cox and IBI, which said agreement would be needed from some lenders to avoid defaults arising from the restructure.
This is because some of the company's loan deals contain restrictions on Aer Rianta's ceasing to retain ownership of Cork and Shannon, and restrictions on the distribution of the company's assets.
She said that if the group failed to secure waivers removing these restrictions, and the debt had to be repaid, 'refinancing would be required' and 'is likely to be costly'.
'A situation could arise whereby refinancing may not be available and in such circumstances, the company would be likely to find itself in an insolvent position,' she added.
Yesterday, the leader of the Seanad, Fianna Fail Senator Mary O'Rourke, said she believed the legislation for the break-up of Aer Rianta was rushed and premature.
