Pope Benedict XVI has made his first public appearance since his shock resignation announcement earlier this week, asking thousands of cheering pilgrims at the Vatican to "keep praying for me".

The 85-year-old pontiff was greeted on Wednesday by a standing ovation and chants of "Benedetto", his name in Italian, at his weekly audience in the Paul VI auditorium, with a prominent banner reading: "Thank You, Holiness."

Benedict said he had made his decision "for the good of the church" adding: "Keep praying for me, for the church and for the future pope."

The pontiff, the first to resign voluntarily in centuries, said he could feel the faithful's love "almost physically in these difficult days".

Vatican spokesman Federico Lombardi has said he expects a new pope in place in time for Easter, which falls on March 31 this year, although no date has yet been set for the secret conclave to elect a new leader of the world's 1.2 billion Catholics.

As rumours fly over front-runners for St Peter's throne, commentators have said age may be a key factor in selecting a new pope, with 117 cardinals eligible to vote for one of their peers.

Later in the day, the pope will celebrate Ash Wednesday mass marking the first day of Lent, his last public mass and one of his final engagements as pontiff.

The mass is traditionally held in the Santa Sabina Church on Rome's Aventine Hill, but has been moved to St Peter's Basilica out of respect for the outgoing pontiff and to accommodate the crowds who will want to mark the end of his eight-year rule, one of the shortest in the church's modern history.

Source: Agencies