Salvadoran officials are planning a new strategy in at least two critical provinces against guerrilla operations that would combine military campaigns with social and economic reforms in an effort to deny the leftist rebels any local support, State Department officials reported.

The officials here said the plan has been under development for about 45 days by the Salvadoran government and described it as "part of a new tactic" to cope with guerrilla operations.

One official said the basic principle behind the strategy is to integrate security and governmental services in "a more sophisticated way" in order to deal with the guerrilla threat. The program would begin with military drives against guerrilla positions in strategic Usulatan and San Vicente provinces. Once the military established its control of the areas, then the government would move in with other programs, such as land reforms and educational programs, according to the sources.

The U.S. adminstration has made no decision yet on whether to assign U.S. civilian to the target areas, although there has been a discussion of that possibility, the officials said.

Sources in San Salvador toldWashington Post correspondent Christopher Dickey that the plan involves technical help from official of the U.S. Agency for International Development and some of the officials may be assigned full-time to the villages. Some sources compared the plan to the Civil Operations and Rural Development Support Agency--known as CORDS--that provided medical care and economic relief to war victims in Vietnam in the late 1960s.

A State Department official familiar with the plan who also had extensive experience in Vietnam said an important difference is that the Viet Cong had guerrilla supporters or infrastructure in many villages but the Salvadorn guerrillas have not developed a major local support structure. Therefore tactics in this case are somewhat different and do not require such a major population control program, according to the official.

State Department officials said the plan was separate from a more ambitious Pentagon program for the country if Congress approves President Reagan's request for $110 million in additional military aid for training this fiscal year.