WASHINGTON — The government announced Thursday it will begin testing a revised nationwide system for checking personal information on every airline passenger, a post-Sept. 11 security initiative that has raised concerns about snooping and false labeling.

The Computer Assisted Passenger Prescreening System (search) seeks to streamline the airport screening process by flagging only those passengers deemed potential security risks. That will benefit the vast majority of travelers by ensuring fewer are stopped, Transportation Security Administration chief James Loy said.

The testing at a secure government location will take up to six months. Loy said he hopes to implement the program in about a year.

U.S. airline trade groups issued statements saying they welcomed the plan because it could reduce security hassles that discourage people from traveling.

A first version of the congressionally mandated system, announced in February, brought protests from privacy advocates. They complained it would give the government access to more personal information than necessary and allow the government to keep it for up to 50 years.

There also was concern people could wrongly be labeled security threats because their names were the same as terrorists and they would have no recourse to fix the error. Loy said the revised system would prevent that from happening because it confirms people's identities.

In response, the Homeland Security Department (search) met with privacy groups as it reworked the plan and hired a chief privacy officer, Nuala O'Connor Kelly.

The version announced Thursday stipulates personal information be deleted from the system shortly after a person completes travel. And less background material will be checked. For example, bank and credit records and medical histories will be off-limits.

People will be able to write or call to find out what's in the database about them, Kelly said. That was not the case under the original plan.

Under the program, an airline passenger would provide name, birthday, address and phone number when getting a flight reservation. That information would be checked against commercial databases and a score would be generated indicating the likelihood the passenger's identity was authentic.

A traveler's personal information also will be checked against government databases to determine if the person is on a computerized terrorism watch list or represents a security risk.

Those deemed an "elevated" or "uncertain" risk will be required to undergo secondary screening with a handheld wand. Anyone deemed a high risk is supposed to be brought to the attention of law enforcement. These can include violent criminals with outstanding warrants.

The information in the commercial database would include what is known as "credit header information," or information at the top of a credit report. It confirms that a person at a certain address holds credit cards with certain companies, but would not reveal details about that person's credit history, said David Sobel, spokesman for the Electronic Privacy Information Center (search). He was among privacy advocates briefed by the government about the plan.

"It's certainly an improvement in some ways, but opening the door to uses beyond aviation security raises some serious concerns," Sobel said, referring to use of the system to track down wanted criminals.

Sobel said he's also concerned that the proposal doesn't require the government to say exactly where it gets personal information.

Jay Stanley, spokesman for the American Civil Liberties Union (search), said the changes were positive. But he remained wary.

"They haven't transformed a dog into a horse, but they've done some grooming on it," Stanley said. "These are potentially fundamental changes in the relationship of the individual and the government, to have the government assigning risk scores to all of us."

Congress ordered transportation officials to come up with an enhanced screening system following the Sept. 11, 2001, attacks. But some of the harshest criticism of the initial plan came from lawmakers, who recently added the stipulation that federal officials test the program before implementing it.