分拆上市指一个母公司通过将其在子公司中所拥有的股份，按比例分配给现有母公司的股东，从而在法律上和组织上将子公司的经营从母公司的经营中分离出去，这时，便有两家独立的（最初的）、股份比例相同的公司存在，而在此之前只有一家公司。这一新设的分拆公司公开发行新股并上市就称为分拆上市。

与分拆相对的操作是兼并收购，兼并收购的英文是merger，故分拆可译为“demerger”，也可译为spin-off，分拆上市可译为“Spin-off listing”或“demerger listing”。

例

The increase in trade and other payables principally reflects higher trade payables due to increased cost of sales and higher expenditure on residential projects in Hong Kong, deposits received for pre-sale units at the AZURA residential project in Hong Kong, reservation fees received for the future charter hire of wind farm installation vessels, the increase in the fair value loss on the put option in relation to the non-controlling interest in Sanlitun Village in Mainland China and higher accrued expenses mainly relating to the spin-off and listing of shares in Swire Properties Limited.

贸易及其他应付款项增加，主要反映因香港住宅项目的销售成本增加及开支上升、香港蔚然住宅项目预售单位所收订金、风力发电站装置船所收的未来租船订金、对中国内地三里屯VILLAGE非控股权益的认沽期权的公平值亏损增加，以及主要与分拆太古地产有限公司股份上市有关的应付开支上升。

Including merger, demerger, acquisition, and share transfer plans, any letter of intent or memorandum of understanding, material contracts, and minutes of board of directors meetings.

重要书件及议事录： 包括合并、分拆、收购或股份受让计划，意向书或备忘录、重要 契约及董事会议事录等书件。