The federal government said yesterday that it will order airlines to turn over millions of passenger records by November so it can begin testing a vast computer program that will hunt for suspected terrorists seeking to board commercial aircraft.

The proposed program, known as Secure Flight, is the government's latest attempt to create an effective computer-assisted passenger screening system. Airlines and privacy advocates fought off previous attempts to develop a system known as CAPPS II, arguing it would violate passengers' privacy. Yesterday, privacy advocates said the government's plans for Secure Flight had not alleviated their concerns.

In rolling out the test program, the Transportation Security Administration is responding to recommendations from the Sept. 11 Commission. The proposed system aims to compare each passenger's reservation information with a list of suspected terrorists more extensive than the one currently used by airlines. The TSA will also attempt to verify each person's identity, so the system will not falsely target travelers who might have similar names to those on the various terrorist "watch lists." Last month, Sen. Edward M. Kennedy (D-Mass.) said he was falsely snared by the watch lists while traveling in March.

The TSA issued several public notices yesterday that began a process to collect by mid-November all domestic passenger records for June 2004 from the nation's 77 airlines. The agency said it will use the data to test the system for 30 days, then develop a more specific plan about how the program should move ahead. The TSA said it expects to launch Secure Flight by spring 2005, although officials yesterday said they knew few details of how it will work.

"We don't have any final decisions made yet," said Justin Oberman, director of the Office of National Risk Assessment, a division of the TSA that oversees the program. "That's why we need to conduct the tests."

The TSA has spent $100 million on the CAPPS II system. Oberman said yesterday that the money has gone toward technology and computer servers that will be used in Secure Flight to handle the high-speed data transactions.

A spokesman for the Air Transport Association, the airline industry's chief lobbying organization, said carriers would review the government's proposed order. But the airlines have the same concerns about how passengers' privacy would be protected and how the airlines would regularly share passenger reservation records with the government.

"We look forward to hearing some more details," said Doug Wills, spokesman for the association, which had opposed the TSA's earlier suggestion that the airlines volunteer passenger records. "If we're going to implement a system like CAPPS II, which on its face presents the potential to develop something that's much smarter and an unobtrustive way of doing security, then industry hopes the government, by this time, has learned some important lessons."

One major change, the TSA said, is that it no longer intends to scan passenger records for violent criminals and people with outstanding warrants. Instead, it will focus only on suspected terrorists. The agency no longer intends to rate travelers with a numerical score and a color code that reflect how much scrutiny they should receive at the checkpoint.

The agency said it still intends to test one of CAPPS II's more controversial elements: the use of commercial databases to help verify passengers' identities. The system will compare reservation records with information contained in commercial databases. The same repositories are used in the banking, home mortgage and credit industries for identity verification, according to a public notice issued by the TSA yesterday. The TSA said it will soon begin the bidding process on contracts to provide the databases and to test the program.

Privacy-rights groups said they were skeptical that the Secure Flight program differed substantially from the TSA's plans to develop CAPPS II. Several groups said the TSA did not explain how a passenger misidentified as a terrorist could contest the error or how a passenger could be removed from the TSA's terrorist watch lists.

Marcia Hofmann, staff counsel at the Electronic Privacy Information Center, a Washington group that advocates privacy rights, said the TSA's public notice exempts the agency from complying with several elements of the federal Privacy Act that entitle people to access records the government maintains on them.

"This is a program where TSA has complete discretion to let you see your information or correct anything that is wrong," Hofmann said.

TSA officials said yesterday that they plan to outline more formal redress procedures after the test period. At a minimum, the agency said, travelers who think they are unfairly targeted by Secure Flight can bring their concerns to the agency's privacy officer.