European Union leaders will try again Friday to agree on who should head the EU's executive body after extended late night talks that ended in deadlock. An EU summit is also engaged in negotiations to agree on a constitution for the enlarged 25-member bloc.

Irish Prime Minister Bertie Ahern, whose country holds the rotating EU presidency, told reporters that none of the candidates who have been mentioned to succeed outgoing European Commission president Romano Prodi has been able to obtain enough support from EU leaders.

"The presidency will make a proposal when they think that there is a name that would command sufficient support," he said. "We're not in that position. I have eight or nine names. I know, because I've talked to all my colleagues, that none of them at this stage would command sufficient support to get a qualified majority voting."

Mr. Ahern says that, as soon as he thinks one of the candidates is acceptable to a majority of the EU members, he will formally submit his name to a vote.

France and Germany have been campaigning hard for Belgian Prime Minister Guy Verhofstadt as the EU's top official, but he has been rejected by Britain, Italy and Poland because of his strong opposition to the Iraq war and, also, because Britain considers him to be a staunch proponent of a federal Europe.

The center-right bloc in the European Parliament, which holds the biggest number of seats there, has proposed Chris Patten, the EU's External Relations Commissioner, for the top job. But France opposes him because his country, Britain, does not share the EU's single currency or take part in its open border regime. The same criticism has been leveled at Anders Fogh Rasmussen, the Danish Prime Minister, whose country also does not use the single currency.

If most leaders had their way, they would select Luxembourg Prime Minister Jean-Claude Juncker. But he has ruled himself out. Others being mentioned are the head of the European Parliament, Pat Cox, of Ireland, and the EU's Justice and Home Affairs Commissioner, Antonio Vitorino, of Portugal. But neither of them have managed to garner enough support among the leaders.

Mr. Ahern said earlier that EU leaders are also narrowing their differences over a draft constitution for the bloc but that serious differences remain, especially over the thorny question of how much voting weight each individual member state will have. Poland and Spain continue to oppose a proportional voting system that would effectively reduce the disproportionate say they now enjoy.

The document was drafted two years ago in an effort to streamline the EU's cumbersome decision-making process, now that it has 25 members. Those negotiations, like the search for a new head of the European Commission, will continue on Friday.