Pentagon officials have thought up a new way to persuade the military services to shut down excess bases: let commanders keep control of the money saved.

Defense Secretary Caspar W. Weinberger likes the idea of providing such incentives, according to defense officials working on the proposal, and may receive the formal recommendations from his deputies by the end of the month.

Up to $200 million a year could be netted by closing and selling off such excess military facilities as old office buildings and small airstrips, one defense executive estimated. This would be four times what the government gained last year from selling military property, he said.

"We're not talking about selling Fort Belvoir, Fort Dix or the Pentagon," the official added, taking note of the alarm bells that sound in Congress when lawmakers learn of any efforts to close bases.

Under the current system, commanders get nothing in return for declaring properties surplus to their needs. Surplus properties are sold off by the General Services Administration under elaborate procedures, with the money going into an Interior Department conservation fund.

Under the new proposal, a commander who said he could do without an office building or airstrip could decide how to spend the money gained from selling the properties. He could thus get a new barracks for the old office building or a repair shop for the airstrip, for example.

The rationale for making such a change was set forth by Lawrence J. Korb, an assistance defense secretary whose responsibility includes bases, in a memo to Weinberger.

"Our intense pressure on the services to close bases produced only a very modest response," said Korb of last year's effort. "Any improvements," he continued, "will have to come from the bottom. They won't come, however, without creating incentives for efficiencies, starting at the base level."

But even Pentagon enthusiasts warn that the idea faces a long obstacle course, starting with the Office of Management and Budget and ending with Congress, which almost certainly would resist any decentralization of the current system for determining which military bases the nation could do without.

When Sen. Charles H. Percy (R-Ill.), chairman of the Governmental Affairs government processes subcommittee, learned about Korb's plan, he immediately attacked it. Percy argued that any money saved from closing military facilities should go toward reducing the national debt.

Percy introduced a resolution in the Senate last October calling for an inventory of surplus federal property, which he said may have a market value "many times" its $1.3 billion original cost. In listing examples of what "should probably be sold" to reduce the national debt, Percy zeroed in on government holdings ranging from Hawaii to the Washington area.

"The Defense Department owns prime beach-front property right in the middle of Waikiki Beach in Hawaii, on which sits a 416-room luxury hotel, used exclusively by vacationing military personnel for super-bargain rates," Percy complained to his Senate colleagues during a floor speech on Oct. 20.

"There are 109 acres of surplus land in Fairfax, Va., which have been sitting unused and unsold for nine years. In Beltsville, Md., there are 5.5 acres of unneeded federal property which has been unused since 1937."