The Pentagon's weapons procurement system is fundamentally flawed and its military chain of command clogged by interservice bickering, according to a report issued with the endorsement of six former defense secretaries.

The report, which recommends major structural reforms in the Pentagon's procurement and personnel systems, is expected to be influential at a time when Congress is calling for defense budget cuts and demanding greater efficiency in weapons procurement.

"We cannot afford to waste scarce defense resources, nor can we afford to allow organizational deficiencies to impair the effectiveness of our military forces," said an accompanying statement by former defense secretaries Harold Brown, Clark M. Clifford, Melvin R. Laird, Robert S. McNamara, Elliot L. Richardson and James R. Schlesinger.

The study, issued by Georgetown University's Center for Strategic & International Studies, aims its sharpest barbs at the five-member Joint Chiefs of Staff (JCS), representatives of the different military branches who are supposed to be the president's top military planners.

The chiefs, according to the report, are unable to rise above their individual service interests to provide "effective, cross-service advice" on weapons development and the formulation of national security strategy. As a result, their recommendations are often "diluted" by efforts to accommodate all parties and are "predictably wedded to the status quo and reactive rather than innovative," it said.

"Each member of the JCS, except the chairman, faces an inherent conflict between his joint role on the one hand and his responsibility to represent the interests of his service on the other hand," the study said.

The panel recommended designating the chairman as the principal military adviser to the president and defense secretary. The chairman would be expected to present a unified military perspective after consulting the service chiefs but "without obtaining unanimous service approval."

On weapons acquisition, the study faults Pentagon planners for failing to supervise and coordinate procurement. Instead, they leave individual services to develop munitions "independently, each according to its own sense of national priorities," it said.

As a result, the panel reported, weapons of "questionable value" to strategic goals often are produced despite poor performance and excessive costs.

Cost overruns are due to "specific deficiencies" within the procurement process, according to the study. It said that contractors often "buy into" a weapons program by keeping initial cost estimates low, knowing they can usually change design and engineering specifications to push up the price later.

Military planners share this incentive for low bids because they want to obtain approval for new weapons programs, the report said, adding that they have little incentive to hold down costs because any savings usually end up as budget cuts in the next fiscal year.

The panel called on the Pentagon to rely more on independent cost estimates before approving a weapons system and to develop an integrated, long-range capital investment plan linking major weapons systems with national strategic goals. Such a plan should include estimates of funds available for defense spending so that competing services would tailor their demands to the budgeted resources, it said.