A spokesman for MUFG said, "the acquisition would cost about 25 billion yen ($276 million)."
Mitsubishi UFJ said last week it would work together with Citigroup on the sale and promotion of Japanese depositary receipts overseas.
Having lost $20 billion in the past year, the US banking giant had previously said it had no plans to sell its Japanese brokerage and investment banking units, or other core businesses in Japan.
Only last year, the US bank embarked on an aggressive push to expand in Japan, buying up a local brokerage, Nikko Cordial Securities, and targeting the country's legions of affluent investors.
In Oct it sold most of its stake in an investment unit, Nikko Antfactory, to Japanese lender Norinchukin Bank [NORB.UL] and trading firm Mitsubishi Corp.
The company has all but closed its consumer lending business in Japan, shutting down more than 30 outlets and 540 unmanned branches.