The State Department has proposed a $53 million "regional counterterrorism program" for five countries in Central America as part of its response to the murders last May in El Salvador of 13 persons, including four U.S. Marines and two U.S. businessmen.

In a memo marked "confidential" to Robert C. McFarlane, President Reagan's national security affairs adviser, the department described the program as one of four options for a supplemental appropriations request and included suggestions for larger and smaller amounts.

As written, the proposal would provide $27 million in military support and $26 million in police training funds to El Salvador, Honduras, Costa Rica, Guatemala and Panama "with a view towards improving counterterrorism capabilities of the host governments," the memo said.

Officials said McFarlane is expected to approve the program for submission to Congress as soon as he returns to Washington later this month. Congressional sources made a copy of the draft available to The Washington Post.

White House officials confirmed they are "actively considering certain proposals" regarding counterterrorism, but refused to comment on the memo.

Drafted shortly after the May 19 shooting in El Salvador, the memo included as one option a $481.7 million Defense Department "wish list" that would make up all the military and economic aid trimmed by Congress from requests during the past three years.

That version, listed as preferred by the Pentagon and the Joint Chiefs of Staff, would be "a dramatic reaffirmation of our determination" to defend the region from a perceived spread of Soviet influence, the memo said. The Central Intelligence Agency "favors a more narrowly focused program," while the Agency for International Development agrees with the State Department, the memo said.

A senior Defense Department official said its recommendation "has been superseded" by subsequent proposals.

"There is no interagency difference on this," he said. "We just have not decided how to package it, how the security assistance problem worldwide will be addressed." A decision is expected after Congress returns from its August recess, he said.

He indicated "general agreement" that the Central American part of the program should follow the State Department proposal. A senior State Department official said that the memo was "an early draft" and that changes were made to ensure compliance with laws aimed at making certain that national police forces do not receive U.S. military aid to use against their own citizens.

Support for the police "would seek to improve the professionalism of host government police forces" and "would include vehicles, communications equipment, supplies and possibly arms," the memo said.

Training, mostly outside the host countries, in intelligence collection and analysis, bomb detection and defusing, hostage rescue, surveillance and countersurveillance, border security and "basic law enforcement" also would be provided, it said. The proposal "should be presented to Congress in a manner that does not prejudice later efforts to obtain substantial economic and military assistance funding," the memo said.

Congressional critics have expressed concern that the proposal is an excuse to funnel additional military aid to a region where Congress has been careful to limit U.S. involvement.

The largest chunk of the funding, $22 million, would go to El Salvador, where preparations against terrorism are "woefully inadequate," the memo said.

"The most serious shortcomings [there] are ineffective command and control, inadequate weaponry and extremely poor mobility, particularly among the security forces. These deficiencies have been regularly exploited by terrorist elements," the memo said.

Spending would include $4.5 million for "aircraft support" for "special operations units," $1.5 million for "fast patrol craft," $4.7 million for communications equipment, $3.9 million on vehicles and $2.1 million for "basic equipment" that would "permit transition to M16 rifles for selected public security forces."

Guatemala would get $5 million, of which $3 million would be for police equipment and training -- primarily vehicles, computer terminals and communications equipment -- and $2 million for military assistance.

Congress has been reluctant to aid Guatemala because of continuing human-rights abuses, but the Reagan administration argues that the military government should be encouraged in its progress toward scheduled elections.

Honduras would receive $11 million, Panama $6 million and Costa Rica $9 million -- including $3.5 million for a Bell 212 helicopter -- under the proposal.