Facebook accounts for one in every six web pages visited by surfers in the UK, a research by web-monitoring firm Experian Hitwise claimed.

The popular social networking site, Facebook, last month claimed that that it had gained more than 500 million members around the world. More than twenty-six million of these members are in the UK.

Figures compiled by Experian Hitwise also showed that Facebook accounts for the most number of page views, but it is the second-most visited site in the UK, after Google.

However, the growth of the Facebook is slowing and the networking site could be approaching its saturation point.

After a steep rise in the number of users in the past couple of years, it appears that Facebook is approaching a point where everyone in the UK who wants an account with the site has one.

According to Hitwise’s Robin Goad, Facebook’s market share actually fell last month. But, the fall could be due to the traditional seasonal lull in Internet traffic seen during holiday periods. Still, there’s a clear-cut flattening of growth visible there. Figures from the past showed that more growth could follow.

But, there is still enough growth potential in other markets of the world to satisfy chief executive Mark Zuckerberg’s aim to have one billion members.