The buyout of the nation’s largest publicly traded subsidiary is expected to trigger a wave of consolidation of listed units, amid ongoing criticism of Japan’s practice of "parent-child” listings.

Nippon Telegraph & Telephone Corp.’s blockbuster ¥4.3 trillion buyout of its mobile unit NTT Docomo Inc. has put the issue of these corporate structures, in which the parent company and subsidiary are both listed entities, back in the spotlight.

While a rarity in many developed markets, Japan is still home to a number of such listings.