Facebook will allow users in the UK to play for real money in its services, opening the door to gambling for the first time now that growth is moderating the first social network in the world.

On Tuesday, Gamesys, an independent game company, released a version of its online bingo for Facebook users in the UK who are over 18, and said it will pay real money to the winners. Gamesys also announced plans to offer a virtual Facebook slot.

Facebook confirmed that it has partnered with Gamesys to allow gambling in its services.

"The real money game is a popular and well-regulated activity in the UK and enables our partners to offer their games to adult users on Facebook in a controlled and safe way", said the social network in a statement.

Facebook spokeswoman Linda Griffin said there are no plans currently in any other country or with any other partner besides Gamesys.

Shee declined to reveal what portion of the proceeds of gambling Facebook would take, but acknowledged that there is a profit sharing agreement between Gamesys and Facebook.

Facebook takes 30 percent of the benefits of transactions or games without real money in its service, as when users buy virtual tractors for cultivation in the popular Zynga Farmville.

The social network, which earns most of its money from online advertising has seen a slowdown in revenue during the past year.

In the second quarter, Facebook reported a revenue growth of 32 percent, a sharp drop in the rate of 100 percent recorded in the same period last year.