WASHINGTON (AP) -- The super-secret National Security Agency confirmed Saturday night that it had a ``serious computer problem'' last week that affected its ability to process intelligence information.

The agency issued a brief statement a few hours after the outage was reported by ABC News, which said its sources characterized the problem as the biggest computer failure in the history of the NSA.

``This problem, which was contained to the NSA headquarters complex at Fort Meade, Md., did not affect intelligence collection, but did affect the processing of intelligence information,'' the agency statement said. ``NSA systems were impacted for 72 hours.''

It said the outage started at 7 p.m. EST Monday and that the system was restored on Thursday.

``There was no evidence of malice or no evidence of a Y2K problem,'' said an agency official who asked not to be identified by name.

``Contingency plans were immediately put into effect that called on other aspects of the NSA system to assume some of the load,'' the agency statement said. ``While intelligence collection continued, NSA technicians worked to recover the IT (information technology) infrastructure. That backlog of intelligence processing is almost complete and NSA is confident that no significant intelligence information has been lost.''

The statement said the agency ``is currently operating within the window of normal operations.''

Until a few years ago, the National Security Agency was so secret there was no public acknowledgment by the government of its existence and employees could be disciplined for merely saying they worked there.

It specializes in electronic intelligence gathering through satellites, telephone intercepts and other methods.

The Defense Department acknowledged earlier this month that it made mistakes in its pre-New Year's Eve testing of a Y2K correction for a computer system that processes imagery from intelligence satellites.

The computer system broke down that night, interrupting the flow of by satellite information for several hours.

However, the Pentagon insisted the trouble did not jeopardize U.S. national security.