Labor Standards Act Article 20

When a business entity is restructured or changes ownership, except for those workers to be retained through negotiations between the old and the new employers, the employer shall terminate labor contracts with the remaining workers by giving the minimum advance notice prescribed by Article 16 and shall pay severance payment in accordance with Article 17. The new employer shall recognize the prior period of service of those workers to be retained.
中文原文 勞動基準法第20條
事業單位改組或轉讓時,除新舊雇主商定留用之勞工外,其餘勞工應依第十六條規定期間預告終止契約,並應依第十七條規定發給勞工資遣費。
其留用勞工之工作年資,應由新雇主繼續予以承認。

English translation for reference only; the Chinese text prevails. Not legal advice.