The number of Iraqi army battalions judged by their American trainers to be capable of fighting the insurgency without U.S. help has slipped from one to none since September, Pentagon officials said Friday.

But the number of Iraqi battalions capable of leading the battle, with U.S. troops in a support role, has grown by nearly 50 percent. And the number of battalions actually engaged in combat has increased by 11 percent.

The U.S. military says its short-term goal is to train more Iraqi units to a level where they can lead the fight, because that allows American troops to focus on other tasks besides combat and could reduce U.S. casualties.

However, in the longer run, the Iraqi military will have to reach a level of full independence so it can take over the battle against the insurgency and allow the Bush administration to withdraw American troops from the country eventually.

When Gen. George Casey, the top U.S. commander in Iraq, told the Senate Armed Services Committee in September that the number of Iraqi battalions capable of fighting independently of U.S. troops had dropped from three to one, the news triggered an uproar among Democrats arguing for an early exit from Iraq.

In a new report to Congress assessing the Iraq situation, the Pentagon also asserted Friday that the insurgency is losing strength, becoming less effective in its attacks and failing to undermine the development of an Iraqi democracy.

The report was written last week, before the bombing of a Shiite shrine and a wave of deadly reprisal attacks. It is the third in a series of reports that Congress requires from the Pentagon every three months.

The Pentagon report claimed important successes against the insurgency and said the term “insurgency” is not necessarily appropriate any more because the synergy that once existed among various rebel elements “is breaking apart.”

The report asserted that the insurgents have alienated most ordinary Iraqis.

“Terrorist attacks have failed to create and spread sectarian conflict,” it said.

The report provided a detailed description of progress in training the full range of Iraqi security forces, but it did not mention how many army battalions are rated “Level 1” – those judged to be fully independent.

It focused on those at “Level 2,” which describes battalions capable of taking the lead in combat against the insurgents, with some U.S. help. Units at “Level 3” are fighting alongside U.S. forces but are not ready to take the lead in planning and execution of missions.

In a briefing for reporters at the Pentagon, Lt. Gen. Gene Renuart disclosed that the number of battalions at Level 1 had dropped from one to zero, while the number at Level 2 had grown from 36 in September to 53 now. The number at Level 3 fell from 52 to 45, in part because some were upgraded to Level 2.