About a third of the FBI agents working on cyber investigations lack the networking and counterintelligence expertise to investigate national security intrusions, the Justice Department's inspector general concluded in a new report.

The report said the FBI's practice of rotating agents among different offices to promote a variety of work experiences hinders the ability to investigate national security cyber intrusions.

The IG's audit, based on interviews of 36 agents in 10 offices, emphasized that the need for a strong cyber security work force in federal government "is more urgent than ever," said Sen. Susan Collins, the top Republican on the Senate Homeland Security and Governmental Affairs Committee.

The FBI has a comprehensive instructional plan in place that includes 12 core courses that an agent must take along with on-the-job training. According to the IG's report, many agents said training was helpful but that they did not have the time to take the required courses. The FBI says it has allowed agents to bypass prerequisite courses when more advanced classes are pertinent to their current case assignments.

Better information sharing by the FBI with other law enforcement and intelligence participants on the National Cyber Investigative Joint Task Force also could improve the government's ability to fend off cyber attacks, according to the report released this week by acting IG Cynthia Schnedar.

The report pointed out that one of the primary findings of the commission that investigated the Sept. 11, 2001, terrorist attacks was that before 9/11 information sharing was inadequate among U.S. law enforcement and intelligence agencies.

Some representatives on the task force were often asked to leave meetings that focused on cyber threats, even though the task force was created to share information, the IG audit said.

FBI officials told the IG that any limitations on information sharing probably were the result of legal restrictions. A task force representative and an FBI agent told the IG's office that some agencies are asked to leave meetings where threats are discussed because a need-to-know policy is enforced.

A Naval Criminal Investigative Service representative said it shared information about a hacker who was using a compromised computer network, but that the FBI did not reciprocate with information as requested. A representative of the Air Force Office of Special Investigations told the IG that the level of FBI information sharing depends on the FBI official to whom a request is submitted.