Bidders for the National Asset Management Agency's entire Northern Ireland loan book have been told it will cost a minimum of €1 billion to buy the €4 billion portfolio. At least four bidders are in the running for the loans, which relate to loans given to Northern Irish developers to buy about 900 properties in the Republic, the North and Britain.

Pimco, the asset management giant with close to $2 trillion under management, is seen as the front-runner for the loan book. Its approach to Nama expressing interest in the portfolio triggered a sale process. Nama has appointed Lazard, an investment bank, to advise it on the process. The deadline for bids is the end of this month.

Due diligence
Pimco began considering acquiring Nama's Northern portfolio before Christmas, so it is considered to be ahead of its rivals in terms of due diligence on a complex group of loans and underlying assets. Other bidders are believed to include American venture capital funds Blackstone, Fortress and Lone Star.

Borrowings from some of the North's best-known developers are included in the sale. These include the McAleer & Rushe Group; Gerard O'Hare, the owner of Parker Greene International; Patrick Kearney's PBN group; and Co Down developer MAR Properties.

Mr Kearney is one of 10 developers known as the Maple 10 who acquired shares in Anglo Irish Bank in 2008.

The best assets in Nama’s Northern Irish book are shopping centres and offices in the North and the UK. There is also a very large land bank included in the sale with sites in the greater Dublin area and on both sides of the Border.

Nama declined to comment on what it said was an “ongoing process”.

Northern Ireland First Minister Peter Robinson, previously a critic of Nama in the North, has said he is closely watching the sale process.

In an interview in February with the BBC he said: “There are certain matters which will be important to Northern Ireland if any company is buying the assets of Nama which relate to Northern Ireland. We will obviously take care to ensure that Northern Irish interests are upheld.”