It was the first time the pontiff has met privately with Blair since Benedict's election last year, but the second time he has met Mrs Blair.

The Vatican gave no details of the meeting, which it described as a private audience.

On Friday Blair held talks in Rome with Italy's new prime minister, Romano Prodi, about the Italian troop withdrawal from Iraq, which Prodi has said will be completed this year.

Mrs Blair met the Pope in April, when she took part in a Vatican conference on children, which he addressed.

Smiling broadly, Mr Blair shook hands with the Pope and then sat down in the papal study for what the Vatican described as "cordial" talks.

The two explored "the contribution which common values between religions can give to dialogue, in particular with moderate Islam, above all on the themes of solidarity and peace, " Vatican spokesman Joaquin Navarro-Valls said.

Also discussed was the need for the international community to help peaceful coexistence and development in Africa, according to NavarroValls.

The "decisive" progress of the peace process in Northern Ireland was also reviewed, the spokesman said.