The federal government's plan to test a computer screening system for airline passengers could be delayed because the program has not yet received a required evaluation by the Government Accountability Office.

The Transportation Security Administration said it is working with the GAO and lawmakers to ensure the agency receives the approvals needed to move forward. Testing was scheduled to begin in the next few weeks.

"We're confident in our ability to remain on schedule," said TSA spokesman Mark O. Hatfield Jr.

This month, the TSA ordered airlines to turn over millions of passenger records so it could test a new airline security program called Secure Flight. The program aims to create a better system of comparing passenger names against government watch lists of known or suspected terrorists. It also seeks to verify each passenger's identity by comparing names against a database of consumer information.

The American Civil Liberties Union, which contends that Secure Flight allows the government to pry too much into travelers' private information, said language in a law funding the Department of Homeland Security prohibits the TSA from conducting some parts of the test until the GAO has evaluated the program.

The law says the TSA cannot test passenger records using databases of consumer information until the agency "has developed measures to determine the impact of such verification on aviation security and the Government Accountability Office has reported on its evaluation of the measures."

"The language on testing of commercial data is crystal clear," said Barry Steinhardt, director of the ACLU's technology and liberty program.

A spokesman from the GAO did not respond to a request for comment yesterday.

The airline security program, which has evolved from a 2002 project called CAPPS II, has been plagued by delays and opposition from privacy rights and civil libertarians. The TSA said it would like to begin operation of Secure Flight in spring or summer 2005, but it faces legal hurdles.

European countries have strict laws that forbid airlines from disclosing passenger information to the government. U.S. airlines could find themselves in a bind if the program forces them to turn over passenger lists to the TSA. The records typically include flight information, passengers' names, telephone numbers, addresses, credit card numbers and traveling companions. Members of the European Union agreed this year to share similar records with U.S. Customs and Border Protection officials, but they have not negotiated an agreement to do the same with the TSA.