Sumitomo Mitsui Financial Banking Inc. said Friday that net profit at its banking unit, Sumitomo Mitsui Banking Corp., plunged 77.2 percent to ¥83 billion in the business year that ended in March as the U.S. subprime-loan upheaval eroded its profits.

However, the banking group's consolidated net profit rose 4.6 percent to ¥461.5 billion due partly to one-time gains earned from merging its leasing affiliates, which pushed up group profits by ¥100 billion.

Subprime-related losses at SMFB — Japan's third-biggest banking group in terms of assets — reached ¥93 billion in business 2007.