MySpace is a personal website tool allowing people to post blogs, music, and videos.

More than 80 million people have registered a MySpace page. News Corp bought the site for $580m last year.

Legal demand

News Corp made the decision to disclose the information to all states after some of the eight states began legal action to demand disclosure.

The firm had previously said such action was required under privacy laws before it could release the information.

Richard Blumenthal, attorney general for Connecticut, told the AP news agency his state had used a subpoena "that compels this information right away - within hours, not weeks, without delay - because it is vital to protecting children".

"Many of these sex offenders may have violated their parole or probation by contacting or soliciting children on MySpace," he added.

MySpace has developed software, called Sentinel Safe, which checks its members against a database of registered sex offenders before removing any profile pages that match.

It has already removed some 7,000 profiles from a total of 180 million.

Spokesman Mike Angus told the AFP news agency: "In addition to removing registered sex offenders from MySpace, our plans have always been to provide the information collected by Sentinel Safe to law enforcement."