Ulster Bank is to sell off 900 distressed mortgages as part of a larger €2.5bn loan portfolio.
Some 95% of the mortgages are two years or more in arrears and all of the loans are the subject of legal action by the bank.
The bank also said it will sell about 2,000 buy-to-let mortgages.
The bank said that customers' existing rights will be transferred with the loans.
The 900 loans represent 0.5% of the bank's mortgage book in the Republic of Ireland.
Yesterday, Sinn Féin finance spokesperson Pearse Doherty said it was his understanding that Ulster Bank will sell the loan book to a “vulture fund”.
Deputy Doherty wrote to Minister Noonan and to Ulster Bank to ask them to stop the sale.
“If true, I am disgusted by this move from Ulster Bank especially the inclusion of family home mortgages in distress,” he said.
“I am calling on the bank to stop this sale.
“At the very least the element of this sale which includes distressed mortgages should be stopped. I believe all political opinion can be united behind that call on Ulster Bank.
“The new law brought in so belatedly last year is not providing adequate protection to homeowners.
“Until it is revised all responsible Irish banks should not be selling any loans but especially ones in distress to vultures.
“Sinn Féin argued at the time for more teeth to be put into the law but after lobbying from vulture funds and others this was diluted.”