Section 99B. (1) In those courts or regions having fewer than fifteen probation officers, all persons serving as chief probation officer or acting chief probation officer shall be allocated to the title of Chief or Acting Chief Probation Officer I, and in those courts or regions having fifteen or more probation officers, all persons so-serving shall be allocated to the title of Chief or Acting Chief Probation Officer II.

(2) All probation officers, except the chief probation officer, shall be compensated in accordance with the provisions of the applicable collective bargaining agreement, pursuant to the provisions of chapter one hundred and fifty E. The salaries of chief probation officers and acting chief probation officers shall be paid by the commonwealth in accordance with a schedule of salaries as recommended in writing by the chief administrative justice of the trial court and filed with the house and senate committees on ways and means.

(3) Upon initial appointment, a probation officer shall be compensated at the minimum of said salary schedule for his group or, if he shall have had prior service as a probation officer or shall, in the judgment of the committee on probation, have had years of similar service in allied fields, the step for such group to which his years of prior service entitle him.

(4) Upon completion of each year of service, a probation officer shall be compensated at the next higher step, if any, of said salary schedule for his group.

(5) Upon promotion (including, in the case of a chief probation officer, a change in his class due to an increase in the number of probation officers his probation office has), a probation officer shall be compensated at the lowest step of his new group which is at least one increment of his new group, but less than two such increments, higher than his salary immediately prior to such promotion, and upon the completion of each year of service in his new group, shall be compensated at the next higher step, if any, of said salary schedule for such new group. Notwithstanding any other provision of this section, no chief probation officer shall receive a salary less than the next increment greater than the salary received by the first assistant chief probation officer in the same court.