Mitsubishi UFJ Financial Group Inc., the world's largest banking group by assets, will be launched Saturday with the merger of Mitsubishi Tokyo Financial Group Inc. and UFJ Holdings Inc. amid growing optimism over the economy.

With the integration of the two holdings firms, the number of Japan's major banking groups will be reduced to three. The other two are Mizuho Financial Group Inc. and Sumitomo Mitsui Financial Group Inc.

Subsidiaries of MTFG and UFJ Holdings -- Mitsubishi Trust and Banking Corp. and UFJ Trust Bank, as well as Mitsubishi Securities Co. and UFJ Tsubasa Securities Co. -- will also be integrated Saturday.