17 web firms have signed a European agreement to improve the safety of under 18s who use social networking sites.

The companies include Bebo, Facebook, MySpace, Google/YouTube, Microsoft and Yahoo as well as Arto, Dailymotion, Giovani.it, Hyves, Nasza-klaza.pl, Netlog, One.lt, Skyrock, StudiVZ, Sulake/Habbo Hotel and Zap.lu.

The agreement has been signed in Luxembourg at the Safer Internet Day organised by the European Commission and is set to "empower teenagers to deal with potential risks they may face online, like cyberbullying or revealing personal information".

Guidelines have been set out covering the usual items such as over 13 age limits and auto privacy options for under-18s. The companies signed up will report on how they've put the policies into place by April 2009.

"The Commission applauds this first European agreement on social networking. It is an important step forward towards making our children's clicks on social networking sites safer in Europe", said Viviane Reding, EU commissioner for information society and media.