1. Optional forms of administration. There shall be the following forms of local civil service administration for the purpose of administering the provisions of this chapter in counties, including civil divisions therein, in certain suburban towns, and in cities in the state:

1. (a) Municipal civil service commissions. A municipal civil service commission shall consist of three persons, not more than two of whom shall at any time be adherents of the same political party. The members of a county civil service commission shall be appointed by the board of supervisors, except that in a county having a county executive the members of the commission shall be appointed by the county executive with the advice and consent of the board of supervisors. The members of a suburban town civil service commission in such a town described in subdivision four of section two of this chapter shall be appointed by the town board of such town. The members of a city civil service commission shall be appointed by the mayor, city manager, or other authority, as the case may be, having the general power of appointment of city officers and employees. Of the members first appointed upon the establishment or re-establishment of a municipal civil service commission, the term of one shall expire on May thirty-first of the first even-numbered year following the date of appointment; the term of one shall expire on May thirty-first of the second even-numbered year following the date of appointment; and the term of one shall expire on May thirty-first of the third even-numbered year following the date of appointment. Upon the expiration of each of such terms, the term of office of each commissioner thereafter appointed shall be six years from the first day of June in the year in which the term of his predecessor expired. If the office of any such commissioner shall become vacant by death, resignation or otherwise, his successor shall be appointed as herein provided for the unexpired term.
2. (b) Personnel officers. The personnel officer of a county shall be appointed by the board of supervisors or, in a county having a county executive, by the county executive with the advice and consent of the board of supervisors. The personnel officer of a suburban town described in subdivision four of section two of this chapter shall be appointed by the town board of such town. The personnel officer of a city shall be appointed by the mayor, city manager, or other authority, as the case may be, having the general power of appointment of city officers and employees. The term of office of a personnel officer shall be six years. A personnel officer shall have all the powers and duties of a municipal civil service commission.
3. (d) Administration by regional civil service commission or regional personnel officer. Any two or more adjoining counties, or any two or more cities in the same or adjoining counties, or any combination of such counties and cities, by written agreement duly approved by the governing board or body of each county or city participating, may establish a regional civil service commission or the office of regional personnel officer. (1) The agreement to establish such a commission shall provide for the manner of selection, appointment and removal of three regional civil service commissioners; provided, however, that no member of such regional commission shall be removed except for cause and after a public hearing. Not more than two members of such regional commission shall at the same time be adherents of the same political party. Of the commissioners first appointed, the term of one shall expire on May thirty-first of the first even-numbered year following the date of appointment; the term of one shall expire on May thirty-first of the second even-numbered year following the date of appointment; and the term of one shall expire on May thirty-first of the third even-numbered year following the date of appointment. Upon the expiration of each of such terms, the term of office of the commissioner thereafter appointed shall be six years from the first day of June in the year in which the term of his predecessor expired. If the office of any such commissioner shall become vacant by death, resignation, or otherwise, his successor shall be appointed for the unexpired term in the manner provided in such agreement. (2) The agreement to establish the office of regional personnel officer shall provide for the manner of selection, appointment and removal of a regional personnel officer; provided, however, that the term of office of such personnel officer shall be six years, and provided further that no regional personnel officer shall be removed except for cause and after a public hearing. (3) Such agreement shall provide for the location of the principal office of the regional civil service commission or regional personnel officer, the employment and status of personnel, the audit and payment of salaries and expenses, the apportionment of costs among participating counties and cities, and such other matters as may be necessary or appropriate. (4) A regional civil service commisison or regional personnel officer shall have all the powers and duties of a municipal civil service commission, and shall administer the provisions of this chapter in the cities and counties, including civil divisions therein, which join in the establishment of the regional civil service agency. (5) Upon the establishment of a regional civil service commission or the office of regional personnel officer, the municipal civil service commission or office of personnel officer, as the case may be, in each of the counties and cities participating shall cease to exist, and all the rights, duties, obligations and functions thereof shall be transferred to and imposed upon such regional civil service commission or regional personnel officer. (6) The written agreement establishing a regional civil service commission or the office of regional personnel officer may be amended from time to time as necessary and for the purpose of admitting additional cities or counties, upon approval of the governing board or body of each of the cities and counties participating in such agreement.