Councillors have given the go-ahead for more than €7 million in sales of apartments at the former Priory Hall site.
Sales have been agreed for 41 apartments in phase one of the refurbishment of the complex now known as New Priory.
A motion from the Anti-Austerity Alliance to halt sales of six units to companies was defeated.
A report from council management stated that the majority of these were for owner-occupiers made through companies listed as Gaughran Homes, Woodview Trading and Harley Holdings.
Cllr Michael O'Brien proposed a motion to stop these sales saying it would set a "dangerous precedent" by selling apartments in the scheme to investment companies for the buy-to-let market.
However Fianna Fáil Cllr Sean Paul Mahon said any of the named individuals on the sales list could be buying to let.
Nine of the 60 apartments refurbished so far are earmarked for social housing, while eight are being returned to original buy-to-let investors as part of the agreement reached with the IBRC.
Council chief executive Owen Keegan warned that the council would lose all credibility if it tried to change the original agreement which was to sell the properties for the highest market value possible.
He said any unpicking of the agreement would allow other parties involved to try and change it as well.
The 41 properties achieved priced ranging from €145,000 for a one-bed unit to €270,000 for a duplex.
Councillors voted by 40 to ten against the change to sales agreements.
The apartment block containing 187 units was evacuated due to fire safety defects in 2011 but refurbishment costing a total of €27m is due to be completed next year.