Sumitomo Mitsui Trust Holdings Inc., the nation's fourth-biggest bank by market value, said it's being investigated for possible insider trading, the second such probe in two months.
"We are fully cooperating" with the Securities and Exchange Surveillance Commission on the case, Sumitomo Mitsui Trust said in a statement in Tokyo Monday, adding that it apologizes to customers and stakeholders.
The SESC will seek to fine a fund management arm of Sumitomo Mitsui Trust for insider trading relating to a public share offering of Mizuho Financial Group Inc. in 2010, Reuters reported May 26, citing knowledgeable sources. The securities regulator believes an employee of Nomura Holdings Inc., an underwriter of the Mizuho sale, told the fund manager about the offering before it was made public, Reuters said.
Keiko Sugai, a spokeswoman for Tokyo-based Nomura, declined comment on the report. A spokesman for the SESC wasn't immediately available to comment.
Sumitomo Mitsui Trust's Chuo Mitsui Asset Trust & Banking Co. unit was found by the SESC in March to have obtained insider information on a share sale by energy company Inpex Corp. Nomura, which managed the Inpex offering, was involved in that case, another source said at the time.
The SESC recommended fining Chuo Mitsui Asset ¥50,000 for that breach and didn't penalize the underwriter, which it didn't identify.