Sumitomo Mitsui Financial Group Inc. is seeking as many as six new hires for a team specializing in underwriting bonds issued by banks that would insulate taxpayers from costs if the lenders later fail.

The pickings are slim.

SMBC Nikko Securities Inc., the investment banking arm of Japan's second-largest lender, expanded the team in March that manages debt sales by financial institutions, said Shunshi Kira, the head of the capital markets division. SMBC's parent is preparing its first bond that can count as higher-level capital under Basel III banking rules, while four overseas banks have debuted similar yen-denominated notes since December.