Mitsubishi UFJ Financial Group Inc. (8306.TO) likely merge its brokerage firm unit with Morgan Stanley's (MS) Japan unit and hold a 60% stake in the combined entity, a person familiar with the matter said Wednesday.

The merger announcement between unlisted Mitsubishi UFJ Securities and Morgan Stanley Japan could be made as early as this week, the person said.

Japan's largest bank invested $9 billion to buy a 21% stake in Morgan Stanley last September.

Both firms have been in talks, aiming to give more details on their relationship by June 30.

-By Atsuko Fukase, Dow Jones Newswires; 813-5255-2957; atsuko.fukase@dowjones.com