Dutch politician Mr Gijs de Vries will be named as the European Union's first counter-terrorism co-ordinator, according to EU diplomats.
EU foreign policy Mr Javier Solana officially decided yesterday that Mr de Vries, a liberal former deputy interior minister who represented The Netherlands in the Convention that drafted a proposed EU constitution, would oversee the bloc's fight against terrorism.
Mr De Vries (48) also played a leading role in setting up the International Criminal Court.
The Taoiseach, Mr Ahern is set to announce the decision tonight, an EU diplomat said ahead of the EU summit which due to start later today.
Mr De Vries will have to monitor and report on the EU action against terrorism in areas ranging from border security to the fight against the financing of terrorism.
Mr Solana had intially envisaged that the post would go to a civil servant but decided to go for someone with a more political profile after the devastating Madrid train blasts that killed 190 and injured nearly 1,900.
In a letter to the Irish EU presidency, Mr Solana said he expected the co-ordinator to present proposals to streamline the work of the EU secretariat on the fight against terrorism; prepare proposals for better co-ordination on security issues; and maintain regular contacts with member states to ensure the best co-ordination between EU and national action.
He made no mention of any role in co-ordinating intelligence co-operation on counter-terrorism, as some countries sought.