In the case of a sale of part or all of an employer’s business, the seller shall be responsible for providing notice for any plant closing or mass layoff in accordance with
section 2102 of this title, up to and including the effective date of the sale. After the effective date of the sale of part or all of an employer’s business, the purchaser shall be responsible for providing notice for any plant closing or mass layoff in accordance with
section 2102 of this title. Notwithstanding any other provision of this chapter, any person who is an employee of the seller (other than a part-time employee) as of the effective date of the sale shall be considered an employee of the purchaser immediately after the effective date of the sale.