The NTMA (National Treasury Management Agency) has sold €1b in bonds as part of its efforts to raise €25 billion in state borrowing this year.
The Government is increasing borrowing as there has been a sharp decline in tax revenues as a result of the economic slump.
Ireland's credit rating was lowered one level to AA+ with a "negative" outlook by Standard & Poor's this year as its finances deteriorated, resulting in an increased cost of borrowing for the government.
The NTMA manages the Government's debt and auctioned €300 million of 4 per cent notes maturing in 2014 to yield an average of 3.90 per cent and an additional €700 million of 4.4 per cent securities due 2019 to yield 5.19 per cent.