The National Lottery Act will have to be revised in order to sell the licence, the Dáil has been told.
Minister for Public Expenditure and Reform Brendan Howlin said he would set out a timeline for the tender.
He said significant proceeds from the sale would be used to fund the National Children's Hospital.
Mr Howlin was responding to a question from Fianna Fáil's Seán Fleming about the sale of the National Lottery Licence and the use of the proceeds.
Mr Fleming said the Department of Health said it would be end of 2017/18 before the project is completed, so he wanted to know if the proceeds were going to be ring-fenced until that time.
The minister said he was exploring a ring-fencing measure for the funds.
Mr Fleming said he was concerned about what might happen to the funds.
He said the minister could not be categorical about the issue, and so the link between the lottery and the hospital had been broken.
Mr Howlin said he would make sure the money was there still, but admitted the delay did pose possible problems.