The ESB will have to renegotiate its €2 billion debt if it is forced to transfer the ownership of its electricity transmission grid to another State entity.
Under the proposals included in the recently-published Government White Paper on energy, the State-owned electricity supplier could have to hand over its transmission system to Eirgrid, the body which currently manages the network.
This would mean that the company would lose an asset valued at €1 billion, and sources say that this could have implications for the terms of its €2 billion debt.
The ESB borrowed the money over the last five years to invest in its network, and has confirmed that it has plans to borrow a similar amount in the near future to cover the cost of further re-investment.
A company source told The Irish Times that should it lose the transmission network, then it would have to renegotiate the terms of its debt.
"The asset base and the regulatory environment would all have been taken into account when the ESB was borrowing money, so any change would mean that the company would have to renegotiate its debts," the source said.
He added that banks and financial institutions like regulatory consistency, so any changes to this or the asset base would be "worrying" from their point of view.
Trade union leaders, including Brendan Ogle of the Amalgamated Transport and General Workers' Union (ATGWU) and David Naughton of the Technical, Electrical and Engineering Union (TEEU), have already expressed concern about the impact of the White Paper proposals on the ESB's credit profile with international banks.
The company does not have a credit rating as such, but has said in the past that it tries to act like an "A-rated" entity.
"A" ratings assigned to businesses by agencies like Standard & Poors are at the higher end of the scale.
In 2003, the ESB borrowed $1 billion (then the equivalent of €800 million) from international institutions through a placing in the US.
The debt carried an average interest rate of 5 per cent at the time.
This figure was in addition to the €1 billion in debt it already had on its balance sheet. Early the following year, the Oireachtas passed legislation allowing the ESB to borrow up to a maximum of €6 billion.
Meanwhile, representatives of trade unions, ATGWU, Amicus, Siptu, UCATT and others met with Minister for Communications, Marine and Natural Resources Noel Dempsey yesterday to discuss the White Paper proposals.
The meeting was the first since Mr Dempsey published the paper earlier this month.
The unions intend to outline their position formally later this week.
