The Government is seeking to raise between €3bn and €5bn from investors in a benchmark Irish bond which will mature in October 2020.
The debt-raising by the National Treasury Management Agency could raise up to a quarter of the State's €20bn borrowing needs for this year.
Separately, the Department of Finance has appointed a new secretary general.
Kevin Cardiff, head of the department's taxation and financial services division, will take up the new role. He replaces David Doyle, who is retiring.