A major US study released Monday put the total number of Christians worldwide at 2.18 billion -- almost a third -- of the estimated global population of 6.9 billion.

Christians make up as big a proportion of the world's population as they did a century ago, but whereas two-thirds of them in 1910 were in Europe, they now are spread more widely throughout the world, the Pew Research Center said.

The United States, Brazil and Mexico led the list of nations with the largest number of Christians, with Russia, the Philippines and Nigeria having the biggest numbers in Europe, Asia-Pacific and Africa respectively.

"Christianity today -- unlike a century ago -- is truly a global faith,"

said the Pew Research Center in the executive summary of its report, "Global Christianity," produced by its Pew Forum on Religion and Public Life unit.

Half of all Christians are Catholics, while 36.7 percent are Protestant and 11.9 percent Orthodox, according to the study.

Nearly 37 percent live in North and South America, and 26 percent in Europe, while 23.6 percent are in sub-Saharan Africa and 13.1 percent in Asia-Pacific. Just 0.6 percent are in the Middle East and North Africa.

The report's findings, posted on the Pew Research Center's website

(www.pewforum.org) were primarily based on a country-by-country analysis of about 2,400 data sources, including censuses and population surveys.

In a report at the start of this year, the center estimated the world's Muslim population at 1.6 billion -- a figure it said was projected to grow by about 35 percent to 2.2 billion by 2030. (AFP)