HARRISBURG (AP) _ Sex offenders who are released from prison should be monitored more widely by global positioning satellite technology so that law enforcement officers do not lose track of them as often, Pennsylvania's auditor general said Tuesday.

Auditor General Jack Wagner urged state lawmakers to require at least five years of GPS monitoring for sex offenders who do not comply with Megan's Law, which requires them to register their address with state police upon their release from prison.

The law should also be revised to mandate similar tracking of sexually violent predators whose victims are children immediately after they are released, Wagner said.

The recommendations were included in a report Wagner released at a Capitol news conference. Auditors determined in early June that the state lost track of more than 900 sex offenders, or about 10 percent of all registered sex offenders, based on apparently outdated addresses in Pennsylvania's Megan's Law registry.

"This is very disturbing to me ... and should be to every Pennsylvanian, and quite frankly, is unacceptable," Wagner said.

GPS systems allow tracking of offenders using a monitor attached to an ankle bracelet and a small tracking device that offenders must carry with them whenever they leave the house. The device transmits information that allows authorities to view an offender's location on a computerized map.

Wagner, who is seeking re-election this year to a second four-year term, previously criticized the state's Megan's Law enforcement in a 2006 audit that found state police had not verified the whereabouts of 700 sex offenders.

State law currently allows, but does not mandate, the use of sex offender GPS monitoring by county probation authorities and the state Board of Probation and Parole.

Republican Sens. Jane Orie of Allegheny County and John Rafferty of Chester County said they are planning introduce legislation that would require wider use of GPS tracking. They said they hope a bill will be considered when the Legislature returns to Harrisburg in the fall.

At least 24 other states have laws requiring GPS monitoring of certain sex offenders, and 14 of Pennsylvania's 67 counties are using GPS tracking for that purpose, Wagner said.

Gov. Ed Rendell's administration had no immediate comment on Wagner's recommendations. Spokesmen for Rendell and the state police said their offices needed to evaluate them.

The probation and parole board is preparing to embark in the coming weeks on a pilot program to test the equipment of eight GPS vendors, spokeswoman Sherry Tate said. She did not know where the testing would be performed or how many sex offenders would be involved.

A previous test program that ran between October 2005 and June 2006 was riddled with problems, such as lost or blocked signals, she said.

"We found the technology was not sufficient at the time," Tate said.

Counties that use GPS tracking typically pay for it by charging sex offenders one-time hookup fees of $30 to $50 and daily rates of $5 to $20 to cover the equipment costs, Wagner said.