Labor Union Act Article 39

The surviving or newly established labor union after the merging shall generally assume the rights and obligations of the labor union which is ceased to exist after the merging.For the labor union which is established after the splitting, the portion of rights and obligations the labor union succeeds shall be concurrently decided by the time when the general meeting of members or member representatives of the original labor union has resolved to spit.
中文原文 工會法第39條
工會合併後存續或新成立之工會,應概括承受因合併而消滅工會之權利義務。
因分立而成立之工會,其承繼權利義務之部分,應於議決分立時由會員大會或會員代表大會一併議決之。

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