(a) In the event property of an employer is sold or transferred to another employer (or to a person that becomes an employer as the result of the sale or transfer) or is partitioned among two or more employers or persons, the individual employer record of such employer shall be prorated among the employer or employers that receive the property (including any person that becomes an employer by reason of such transaction or partition), in accordance with any agreement among the respective parties (including an agreement that there shall be no proration of the employer record). Such agreement shall be subject to the approval of the Board. Where the employer acquiring the assets is an existing employer under part 202 of this chapter, that employer's individual employer record will take into consideration the acquired assets no earlier than the calendar year following the year of the Board's determination, unless an agreement among the respective parties provides otherwise. Where the employer acquiring the assets becomes an employer under part 202 of this chapter by virtue of such acquisition, the individual employer record for such employer shall consider the acquired assets as of such person's employer effective date, subject to any agreement between the respective parties and the provisions of paragraph (b) of this section.

(b) There shall be no transfer of the employer record where an employer abandons a line of track in accordance with the provisions of the Interstate Commerce Act and the applicable regulations thereunder, and a new entity, found by the Board to be an “employer” under part 301 of this chapter, is formed to operate or continue service over such line; the Board will assign to such entity a new-employer contribution rate in accordance with section 8(a)(1)(D) of the RUIA and § 345.304 of this part.