A senior White House official said today that President Reagan is not expected to increase the number of military trainers in El Salvador beyond the current self-imposed limit of 55, but that "less than a dozen" other military personnel may be added to the U.S. contingent there.

The official, who asked not to be identified, told reporters here that Reagan has not reached a decision on the level of trainers and other military personnel in El Salvador.

The official said that "we did ask for specific recommendations" from various departments on "whether we need to increase the number of trainers" but that the recommendations have not reached Reagan.

"I do not look for any increase above the 55 limit for people doing the training," the official said.

But he left open the possibility that Reagan may add fewer than a dozen military personnel in functions other than actual training.

While the administration has placed a self-imposed limit on the number of trainers, there is no similar ceiling for other military personnel in El Salvador.

The Washington Post reported today that an interagency review concluded that the new U.S.-run military training facilities and program in Honduras could be used for stepped-up training of Salvadoran soldiers, obviating the need for more trainers inside El Salvador.

The review recommended, however, that the definition of "trainers" be tightened to exclude some communications or administrative specialists now classified as trainers. This would leave room for a slight increase in the number of trainers working directly with Salvadoran forces fighting leftist guerrillas.

The official, who briefed reporters here while Reagan is vacationing at his nearby ranch, insisted that the administration is not playing a "numbers game" by shifting personnel among different categories.

But the official made it clear that the administration wants to ensure that the self-imposed limit of 55 trainers is composed only of personnel directly involved in training.

White House spokesman Larry Speakes said the administration wants to be "absolutely certain" that military personnel are counted accurately and that "people who are counted as trainers are people who are training."

The administration official said non-training personnel whose numbers could be increased may include Marine guards at the U.S. Embassy, personnel working for the defense attache or members of a U.S. medical unit sent to El Salvador.

But the official said he is "reluctant" to speculate whether such an increase actually would be made.

According to this official, the U.S. military presence in El Salvador today consisted of 102 persons--49 trainers, 26 members of the medical team, 17 Marine embassy guards, five persons working for the defense attache and five in the embassy's military group.