ISLAM has overtaken Roman Catholicism as the biggest single religious denomination in the world, according to new figures.
In its newly-released 2008 yearbook of statistics, the Vatican claims Muslims now make up 19.2 per cent of the world's population with Catholics at 17.4 per cent.
In the Vatican newspaper, L'Osservatore Romano, Monsignor Vittorio Formenti, wrote: "For the first time in history we are no longer at the top: the Muslims have overtaken us."
However, he said that if all Christian groups were considered, including Orthodox churches, Anglicans and Protestants, then Christians made up 33 per cent of the world's population – or about two billion people.
The Vatican recently put the number of Catholics in the world at 1.13 billion. It did not provide a figure for Muslims, estimated at about 1.3 billion.
Numbers for other major world religions include an estimated 785 million Hindus, 360 million Buddhists and 17 million Jews.
Mgr Formenti said that while the number of Catholics as a proportion of the world's population was fairly stable, the percentage of Muslims was growing because of higher birth rates.
However, Bashir Maan, convenor of the Muslim Council of Scotland, said he thought that Islam was probably the largest religion in the world.
And he said it was not just down to higher birth rates, but because more people were converting to Islam.
"It is difficult to get a true figure of the number of Muslims in the world because trying to establish numbers in underdeveloped Muslim countries is very difficult.
"But if proper figures could be obtained from those countries then I think it would show Islam as the largest religion in the world."
He said that people were attracted to the religion looking for "spiritualism". He conceded that recent terror attacks had turned many people against Islam – but added the religion had benefited from other people studying the religion to find out its true message.
"These people are discovering a tolerant and accommodating religion," he said.
A spokesman for the Catholic Church in Scotland said it was important to look beyond the figures.
"While it is a little unseemly to swap figures, a more realistic comparison would be between the Christian population of the world and the Muslim population, a comparison which would show the Christian world to be significantly bigger," he said.
He added: "Christianity and Islam are both 'religions of the Book' – they share their origins in the Old Testament – and although there are some hot spots of tension in the world, there is also a wide area of common concern for Christians and Muslims, especially on such issues as the family and the sacredness of life."