Tokyo prosecutors plan to indict SMBC Nikko Securities Inc. for alleged market manipulation, according to the Nikkei newspaper, in what¡¯s set to be a blow to one of Japan¡¯s biggest brokerages and its second-largest megabank.

The prosecutors determined employees weren¡¯t sufficiently supervised despite having conducted allegedly illegal trades repeatedly, the newspaper reported, citing several people that it didn¡¯t identify.

The brokerage unit of Sumitomo Mitsui Financial Group Inc., the country¡¯s No. 2 lender, is under investigation for alleged market manipulation.