In the event that any person acquires by purchase, merger, consolidation, devise, inheritance or otherwise, a distinct, severable, identifiable and segregable part of the business of an employer and continues such an acquired part of the business of the predecessor, the successor shall succeed to that portion of the employment benefit experience record of the predecessor which is attributable solely to the portion of the business which was acquired, except that such a succession to the reserve account attributable to an identifiable portion of the business of the predecessor shall not occur unless the successor is an employer at the time of the acquisition or becomes an employer within the quarter in which the succession occurs. Provided, however, no partial transfer of any employment benefit experience record shall be made unless a request is entered therefor by both the predecessor and the successor employer. The Commission shall prescribe by regulation a period within which notification of such acquisition shall be given and the method by which the experience to be transferred shall be computed.