The global number of Internet users has surpassed one billion with China accounting for the largest population of Web surfers, digital research firm comScore Inc. reported on Friday.

"Surpassing one billion global users is a significant landmark in the history of the Internet," comScore chief executive Magid Abraham said in a statement.

"It is a monument to the increasingly unified global community in which we live and reminds us that the world truly is becoming more flat," Abraham said.

"The second billion will be online before we know it, and the third billion will arrive even faster than that," he said.

ComScore said the total number of Internet users had surpassed one billion in December.

The actual number of Web surfers is probably higher than that as comScore said its figures were based only on the number of Internet users aged 15 and above working from home or work computers.

They did not take into account traffic from public computers such as Internet cafes or access from mobile phones or personal digital assistants.

ComScore said the Asia-Pacific region accounted for 41 percent of the one billion global Internet users, followed by Europe (28 percent), North America (18 percent), Latin America (seven percent) and the Middle East and Africa (five percent).

China had the largest population of Internet users with nearly 180 million people going online in December, follwed by the United States with 163 million, Japan with 60 million, Germany and Britain with nearly 37 million each and France with 34 million.

India was next with 32 million Internet users followed by Russia (29 million), Brazil (28 million), South Korea (27 million), Canada (22 million) and Italy (21 million).

Google was the most frequently visited Web property in December with 777.9 million unique visitors, followed by Microsoft sites (647.9 million visitors), Yahoo! (562.6 million visitors), AOL (273 million) and Wikimedia (273 million).

ComScore said Facebook.com had grown by 127 percent in the past year and welcomed 222 million visitors in December, making it the top social networking site worldwide.