WASHINGTON - Struggling to finish a politically thorny task, the base-closing commission tackled a shake-up of the Air National Guard on Friday after - in a setback for the Pentagon - it voted to keep open Ellsworth Air Force Base in South Dakota.

The nine-member panel endorsed the concept of restructuring the Air Guard but did not accept Defense Secretary Donald H. Rumsfeld's proposal in its entirety. Instead, commissioners largely crafted their own plan that shuffled personnel and aircraft around dozens of units - both large and small - in states from coast to coast.

"In parts, we concur with their recommendations. In other areas, we're making some changes," Chairman Anthony Principi said.

Rumsfeld's plan had called for nearly 30 Air Guard units scattered around many states to lose their aircraft and flying missions, prompting howls of protests from governors and a few lawsuits.

Instead, the panel restored planes to some units, and in doing so, kept open some Air Guard and Reserve bases that would have closed under the Pentagon plan.

"We have established more flying units than the secretary recommended, but we still could not get a flying unit in every state," Commissioner Harold Gehman said. However, the commissioners pointed out that not all states have Air Guard units, and, therefore, wouldn't need airplanes.

The panel worked well into the evening Friday as members tried to conclude the high-stakes decisions in the first round of U.S. military base closings and consolidations in a decade. Votes by the commission have brought sighs of relief and exasperation from communities across America.

By Sept. 8, the panel must send its final report to President Bush, who can accept it, reject it or send it back for revisions. Congress also will have a chance to veto the plan in its entirety, but it has not taken that step in four previous rounds of base closings. If ultimately approved, the changes would occur over the next six years.

Air Force officials said their overall plan - affecting active duty, Air Guard and Air Reserve bases - was designed to make the service more effective by consolidating weapons systems and personnel as it moves to a smaller but smarter fleet in the future.

Under the Pentagon's Air Guard plan, units without aircraft would have received other assignments such as expeditionary combat support roles. They also would have retained their missions of aiding governors during statewide emergencies.

The commission began work on the Air Guard plan just as a federal judge in Pennsylvania ruled that the Pentagon lacks the authority to close an Air Guard unit located at the Naval Air Station Willow Grove in Pennsylvania without Gov. Ed Rendell's approval. The judge declared the plan for that unit "null and void."

Aware of the ruling, the commission labored on anyway - and twice voted on the fate of the Naval Air Station Willow Grove. Ultimately, the panel decided to close the base, but keep intact the Air Guard unit that was subject to the lawsuit and create an Army Guard and Reserve center. However, that unit would exist without aircraft.

Commissioners denied the lawsuit affected their ruling.

In May, the Pentagon proposed closing or consolidating a record 62 major military bases and 775 smaller installations to save $48.8 billion over 20 years, make the services more efficient and reposition the armed forces. The Air Guard proposal emerged quickly as the most contentious issue.

The decision to spare Ellsworth Air Force Base was a blessing for South Dakotans, who feared losing some 4,000 jobs, and a victory for Sen. John Thune and the state's other politicians, who lobbied vigorously against closure. Thune, a freshman Republican, unseated then-Senate Minority Leader Tom Daschle partly on the strength of his claim that he would be better positioned to help save the base.