Dozens of firehouses and hundreds of police stations have been rebuilt in Iraq. Thousands of schools are fixed. Millions more Iraqis have access to cellular telephones.

But oil and gas production, which fuels Iraq's fragile economy, has yet to return to levels before the U.S.-led invasion in March 2003 despite slight improvements in recent months.

The main reason: insurgent attacks on facilities.

And a review of the health care network finds that more than three-fourths of projects are finished but "progress has been significantly diminished by security and management problems," according to a report being released Monday.

A contractor in one case that Stuart W. Bowen Jr., the special inspector general reviewing the rebuilding in Iraq, highlighted set out to build 150 health clinics, but now plans to finish only 20. An audit found that only six clinics are completed even though 75 percent of the money has been spent.

These are the mixed results of Bowen's latest report on rebuilding, an effort in which the United States has invested about $20 billion.

The report comes as the Bush administration voices fresh hopes for progress in Iraq now that the country's parties have broken a four-month stalemate and chosen Nouri al-Maliki to become prime minister.

Reviving the country's feeble economy could help prompt the withdrawal of some of the 132,000 U.S. troops in Iraq, which would be popular with many voters and members of Congress facing re-election this fall.

"Despite certain setbacks, chiefly caused by security problems, the overall picture conveys a sense of substantial progress in the relief, recovery and reconstruction of Iraq," Bowen said.

Nevertheless, he said, "Insurgent activity continues to impede ongoing reconstruction projects and interrupt their transition to Iraqi control."

Bowen attributed progress so far to the fact that U.S. and Iraqi officials increasingly are working together on reconstruction projects as the new government has taken shape.

Although Bowen expects most projects to be turned over completely to the Iraqi government by years' end, he said, "For transition to succeed, Iraqi must ensure that its ministries are ready to receive and capably manage completed projects."

That, he said, includes safeguarding facilities from insurgents, who have sabotaged progress by attacking work sites, including oil, gas and electrical facilities.

In an audit accompanying the report, Bowen found that Task Force Shield — an effort to help Iraqis protect 340 important oil, gas and electrical facilities, about 4,340 miles of pipeline and about 8,680 miles of transmission lines — "failed to adequately meet its goals."

Updating his previous reports, Bowen said fewer than half of the reconstruction projects in those areas are finished, and it could take an additional two years to complete all construction.

Overall power generation capacity available to the electrical grid is currently below the estimated prewar level, Bowen found, even though Iraqis outside of Baghdad are getting more hours of power on average than they did before the war. Those inside Baghdad are not.

Bowen attributed the poor oil and gas production to the ability of insurgents to attack facilities and to investors' hesitance to engage in that part of Iraq's economy, given the tenuous security environment and the fledgling state of the government.

The report is the first in which Bowen has issued results on several other parts of the reconstruction effort.

Bowen praised "steady improvement" in rebuilding the justice system, saying that more than 600 police and fire stations, prisons, and court houses have been constructed. But, he added, "The overall security situation ... remains volatile."

In the transportation and communication sectors, Bowen reported that 80 percent of projects to rebuild, refurbish and reopen Iraq's ports, railways, roads, bridges and airports have been completed and that almost 5.2 million more Iraqis now have access to mobile phone service than before the war started.

On the downside, he said that only 4 percent of trains run each day even though repairs at most of Iraq's 107 railway stations are completed — another example of security issues hindering progress.

Additionally, Bowen reported that more than 90 percent of education projects have been completed, including the repair of 5,108 schools and the training of more than 47,000 teachers.