Mitsubishi UFJ Financial Group Inc. is considering a bid for Bank of New York Mellon Corp.'s corporate trust arm, sources with knowledge of the matter said.

The sources, who asked not to be identified as the deliberations are private, didn't say how much Mitsubishi UFJ may offer. BNY Mellon, the world's largest custody bank, is working with Goldman Sachs Group Inc. to find buyers for the unit, which could fetch at least $2.5 billion, a source said last month.

Low interest rates and a shrinking population at home are prompting Japan's biggest banks to expand abroad. Mitsubishi UFJ, which owns about 22 percent of Morgan Stanley and runs San Francisco-based UnionBanCal Corp., is looking to invest in the United States and Asia, Deputy President Masaaki Tanaka said in February.