London-based online gambling operator Gamesys has developed the the Bingo Friendzy app for Facebook, which allows users aged 18 and over to play games for cash prizes. Facebook will allow users in Britain to wager real money on its service.

Facebook said only its UK members would be able to view the app. Gamesys also announced plans to offer virtual slots gambling on Facebook.

It is not clear what portion of the revenue Facebook would take from the gambling on the Gamesys games.

Facebook takes a 30 percent share of revenue for transactions on non-gambling games on its service, such as when users purchase virtual tractors and seeds in Zynga's popular Farmville game.

Facebook makes the majority of its money from online advertising and has seen its revenue growth slow sharply during the past year.