Permanent TSB said today it has raised €400m in fresh debt.
Since the New Year, the lender has raised over €3.6 billion in debt secured against its UK and Irish mortgage books.
It said that €1 billion is new debt being financed for the first time while €2.6 billion is accounted for by the refinancing of maturing debt.
The bank said it raised the money in unguaranteed debt in a private deal using Irish residential mortgages.
A spokesman for PTSB said the bank's deposit book rose €1 billion in the second half of the year.
Ireland's main banks - AIB and Bank of Ireland - have followed the NTMA back into capital markets in recent months.
Permanent TSB said the deal was signed in the last few days with one of the leading international banks.
''We’ve had good success in recent weeks in raising money on the back of our UK and Irish mortgage books. These transactions, and our strong deposit growth, demonstrate our ability to finance our operations on an ongoing basis without reliance on the bank guarantee,'' the spokesman said.