Whenever any person or other legal entity has in any manner succeeded to or has acquired substantially all or a distinct and severable portion of the business of another, as provided in Sections 41-31-100 and 41-31-120, the base rates of contributions are computed as follows:

1. (a) If the successor is not already an employer at the time of the acquisition, the base rate of contributions applicable to the predecessor employer with respect to the period immediately preceding the date of acquisition, if there is only one predecessor employer, shall apply to the successor employer for the remainder of the calendar year. The base rate for the subsequent calendar year is computed based upon the employment benefit experience record of the predecessor or upon the combined employment benefit experience record of the predecessor and the successor, if applicable, as of June thirtieth of the year in which the acquisition occurred.
2. (b) If the successor is not already an employer at the time of the acquisition and there is more than one transferring employer with a different base rate, the successor employer is assigned the base rate of that transferring employer who has the highest base rate with the base rate being applicable until the end of the quarter in which the succession occurs.

3. (c) If the successor is already an employer at the time of the acquisition, the base rate of contributions applicable at the time of the acquisition to the successor employer shall continue to be applicable until the end of the quarter in which succession occurs.

   For the purposes of items (b) and (c), the base rate as assigned continues in effect until the first day of the next calendar quarter immediately following the acquisition, at which time the commission shall compute a base rate based upon the combination of that portion of the employment benefit experience record acquired from the predecessor with the employment benefit experience record of the successor, subject to the provisions of this article, which base rate is applicable to the successor from the first day of the quarter for the remainder of the calendar year. If the acquisition occurred prior to July first, the base rate for the subsequent calendar year is computed based upon the combined employment benefit experience record as of June thirtieth of the year in which the acquisition occurred; if the acquisition occurred subsequent to June thirtieth, the base rate for the subsequent calendar year is computed based upon the combined employment benefit experience record as of December thirty-first. All base rates thereafter are computed upon the basis of the combined employment benefit experience record and at such time as provided in Section 41-31-40.