The Vatican has hosted a major gathering of different Christian religions, which it says will be the most important ecumenical event during its year-long celebrations to mark Christianity's third millennium.

More than 20 non-Catholic representatives attended the ceremony including the head of the Church of England, the Archbishop of Canterbury, Dr George Carey.

Dr Carey and Metropolitan Athanasios, representing Ecumenical Patriarch Bartholomew I, the spiritual leader of the world's Orthodox Christians, knelt in silent prayer just behind the Pope after helping him push open the Holy Door of St Paul's Outside the Walls Basilica.

Only one cushion for kneeling was provided - for the Pope - underlining the surprise decision of the Anglican and Orthodox representatives to get down on their knees, too, in a gesture of unity.

"Unity! Thank you!" the Pope shouted out with joy in impromptu remarks after reading his homily.

An American woman, Frances Alguire, greeted him as president of the World Methodist Council.

"We know we are brothers still divided, but we have placed ourselves with decisive conviction on the path that leads to full unity," the pope told participants, who also included Lutherans and Pentecostals.

"We ask pardon of Christ for all that which in the history of the church prejudiced his design of unity," the Pope said.

Arriving, Pope John Paul crossed the basilica's courtyard with an unusually brisk step.

Since hip surgery in 1994, the Pope has experienced difficulty walking.

Difficult relations

At the end of the ceremony, Pope John Paul launched into an improvised recollection of the joy he felt in Bucharest, Romania, in May - the first largely Orthodox country he has visited in his 21 years of world travel.

Relations with the Russian Orthodox Church have proved more difficult, with disupte over church property seized by the Communists.

The Orthodox have accused the Vatican of aggressively trying to win souls in the former Communist countries.

However, a representative of the Orthodox patriach in Moscow did attend Tuesday's ceremony.

While this gathering was to encourage Christian unity, there will be other church ceremonies in Italy promoting dialogue between Christians and Jews.

In March, Pope John Paul is due to make a much longed for visit to Israel