A permit to continue sponsoring bingo games has been granted to the controversial Montessori School of Alexandria Inc. because Alexandria's special bingo prosecutor granted the school immunity from prosecution for any past law violations, it was disclosed last night.

The immunity was granted by prosecutor Edward J. White on condition that the school's founder, Dirgham Salahi, stay away from the games, which he once operated on the school's behalf, according to Alexandria City Council members.

Salahi was a key witness at the trial of Alexandria Commonwealth's Attorney William L. Cowhig last month that resulted in Cowhig's acquittal of bribery charges. Salahi testified he paid Cowhig a total of $32,000 in exchange for protection for the bingo games that supplied badly needed revenue to the school.

City Council members Robert L. Calhoun and Donald C. Casey and City Manager Douglas Harman said they were informed of the unusual immunity grant for the first time last night by Albert H. Grenadier, the school's attorney.

Salahi had been granted immunity from prosecution, before Cowhig's trial.

White could not be reached for comment.

Renewal of the bingo permit was initially denied by City Finance Director Howard Holton, but he reversed that decision Friday and said in a memo there was no reason why the permit should not be granted.

Casey, a frequent critic of the school because of its reliance on bingo as a fund-raising activity, has said in the past that he would oppose issuance of a permit to the school because of "irregularities" revealed in part at the Cowhig trial.

The council last night accepted by a 4-to-3 vote a proposal to raise the salaries of coulcil members from $625 to $750 per month, and to increase the salary of the mayor from $683 to $791 per month. The measure was introduced by council member along with council members Nora Lamborne, Casey and Mayor Frank E. Mann. Opposing the measure were members Ellen Pickering, Nicholas Colasanto and Calhoun.

The pay raises will become effective only after next spring's council elections.