NAMA's Northern Ireland portfolio of loans and properties will have a face value of between €3.5bn and €4bn depending on what assets are sold.
Data published by NAMA last month states that the agency acquired loans secured by properties in Northern Ireland with a nominal value of €4bn in 2010. It paid €1.26bn for the loans, the document shows.
A media report in the specialist real estate publication CoStar this week said the portfolio may be smaller, at €3.5bn based on the unpaid balance of the debts involved.
A source said changes since NAMA acquired the assets, currency effects and the decision on what assets are included in the sale mean the final size is not yet clear.
It is known that NAMA has already recouped €170m through asset sales north of the Border, reducing the size of the potential portfolio. Any loan repayments since 2010 would also lower the balance nominally owned.
At the same time the agency has also advanced new loans to Northern Ireland-based developers, though that includes work done outside the six counties.
The final size of the portfolio put on the market through Lazard will also depend on whether loans advanced to Northern Ireland-based developers for schemes south of the Border and outside Ireland are included, and whether loans advanced by banks to customers on this side of the Border for investments in the North are included in the sale.
According to the agency's data, the €1.26bn it paid for the loans breaks down as €780m linked to investment properties, including shops (€220m), offices (€220m) and other commercial properties (€340m). Built residential properties accounted for €130m, with hotels accounting for just €10m. More than a fifth of the total, €280m, was secured on land, with an additional €60m for development sites.