The Revenue Commissioners have told ex-shareholders in now nationalised bank Anglo Irish they can write-off their losses on the stock against their tax bills.

The shares, while not officially worthless, are believed to have very little value, although there is still some over-the-counter trading in Anglo stock in the US. The government has yet to appoint an assessor to make a judgement on how much the shares are worth, if anything.

Revenue has told tax practitioners that Anglo shares are considered to be of "negligible value" and consequently a loss for 2009 may be calculated.

The write-offs can only be taken against capital gains which should mean that the hit to the exchequer is relatively limited. Capital gains mostly occur on share transactions and property sales, both of which have been hit hard by the global downturn.

The Revenue Commissioners have told the practitioners that if at a later stage the shares do acquire a value this will be regarded as a "disposal" and treated accordingly. The valuation of Anglo shares falls under the terms of the Anglo Irish Bank Corporation Act 2009.

Foreign institutions would not likely be allowed to charge to Irish tax on the Anglo shares so the only benefit to them would be if they could set Anglo losses against gains in their own country.