Moody's Japan K.K. assigned first-time issuer ratings of A1/P-1 to Mizuho Securities Co. Ltd. and its overseas affiliates Mizuho International Plc and Mizuho Securities USA Inc., or MSUSA.

The outlook is stable.

Moody's said Jan. 27 that the change in MSUSA's ownership structure in July 2016 does not impact government support or the strategic importance of the subsidiaries to Mizuho Financial Group Inc.'s global operations. MSUSA became a wholly owned subsidiary of Mizuho Americas LLC, which is in turn owned by Mizuho Bank Ltd. Prior to the change, MSUSA was 70.5% owned by Mizuho Securities and 29.4% by Mizuho Bank.

Mizuho Securities remains a 95.8% owned subsidiary of Mizuho Financial, and Mizuho International remains a wholly owned subsidiary of Mizuho Securities. The issuer ratings of the units were aligned with the ratings for Mizuho Securities, the group, Mizuho Bank Ltd. and Mizuho Trust & Banking Co. Ltd.

An upgrade of the ratings is unlikely over the next 12-18 months as the ratings are at the same level as Japan's sovereign rating. However, the rating agency may downgrade the ratings if it sees a downgrade in the sovereign ratings or the group's ratings.