The Senate Foreign Relations Committee yesterday gave tentative approval to a resolution calling on factions in El Salvador to negotiate an end to the civil war there.

The resolution, a compromise drafted after several days of debate and rewording, seeks to establish a policy of favoring negotiations to stop fighting between government troops and guerrilla forces.

The final wording is understood to be offensive to the Salvadoran government, which has regarded a request to open negotiations with leftists as an example of foreign interference.

The State Department also had objected to a call for negotiations, but Sen. Nancy Landon Kassebaum (R-Kan.) said yesterday that she has been assured that the resolution is acceptable to the department. A formal statement on the issue will be prepared today, a State Department spokesman said last night.

Use of the word "negotiations" has become delicate, with the State Department strongly opposing it if it were intended to mean a method of distributing political power among Salvadoran insurgents and pro-government forces.

The final version referred to negotiations to resolve the conflict, not the ultimate distribution of political power. It said U.S. policy should be to "encourage all parties to the Salvadoran conflict to begin good-faith negotiations for the purpose of bringing an end to the hostilities and achieving a peaceful and Democratic solution to that conflict."

Five members of the committee approved that wording in a voice vote, indicating that the resolution will pass in a full committee vote.

The resolution also opposed efforts by Cuba to extend its political system into the hemisphere by force or threat of force.