Social networking site MySpace has unveiled a new initiative aimed at keeping underage users safe online.

The Joint Statement on Key Principles of Social Networking Sites Safety (PDF) sets out guidelines for site owners and US law enforcement agencies.

The plan calls for tighter age verification systems and the increased online presence of law enforcement groups.

MySpace has vowed to improve its age verification system and make the profiles of all users between the ages of 14 and 17 set to 'private' by default. The site has also promised to develop new parental control software.

Individual US states will beef up their presence on MySpace by establishing a 24-hour hotline and forming a new task force charged with improving safety controls on the site.

The programme has the support of attorneys general from 49 US states along with the District of Columbia.

Texas attorney general Greg Abbot emerged as the only detractor, telling reporters that the new guidelines would be inadequate fully to protect children.

Keeping sexual predators off MySpace has proved a major issue for the social networking site.

Tens of thousands of sex offenders have been identified on the site, prompting the deletion of 29,000 profiles in July last year.