系けい列れつ子こ会がい社しゃ

• 子こ会がい社しゃ

  子会社 is a general subsidiary, while 系列子会社 specifically belongs to a keiretsu group with stronger affiliation.

• 系けい列れつ

  系列 refers to the corporate group or affiliation network itself; 系列子会社 is a company within that network.

Compound of 系列 (keiretsu, 'corporate group') and 子会社 (kogaisha, 'subsidiary').