Sumitomo Mitsui Financial Group Inc. is on track to be the biggest manager of yen-bond sales for the first time, suggesting its 2009 acquisition of Citigroup Inc.'s operations in the business is bearing fruit.

Japan's second-largest bank managed ¥963.5 billion ($7.7 billion) in local currency-denominated debt sales this year, giving it a 19 percent share, data compiled by Bloomberg show.

Morgan Stanley, which operates two joint ventures with Mitsubishi UFJ Financial Group Inc. in Japan, ranked No. 2 for nongovernment issuance, down from No. 1 in the first half of 2014.