At least four Japanese companies including Toyota Finance Corp and Sumitomo Mitsui Trust Holdings Inc removed Nomura as bond managers after the regulator’s move, according to underwriter announcements.

Nomura’s shares tumbled as much as 7.4% Monday morning amid a broad sell-off in Japanese stocks.

This is the second time this year that Japanese issuers have cut underwriters due to their regulatory troubles. It follows similar moves after Japan’s Financial Services Agency penalised Mitsubishi UFJ Morgan Stanley Securities Co in June.

The value of corporate bonds issued in Japan’s domestic market this fiscal year has already exceeded ¥10 trillion (US$68 billion), a record for the first half, and the coming months are typically a busy time for brokerages.