Morgan Stanley is doubling down on its efforts to help Mitsubishi UFJ Financial Group Inc. replicate the U.S. lender’s highly successful wealth management business in Japan, where competition to serve rich clients is intensifying.

The New York-based lender has dispatched Darren Spencer, the former chief operating officer of Morgan Stanley Private Wealth Management, to Tokyo to train staff and develop expertise at Japan’s largest lender. The two banks set up the Mitsubishi UFJ Morgan Stanley Securities Co. joint venture in 2010, which offers retail clients investment services.

At the end of December, the joint venture managed ¥40.7 trillion ($373 billion) of client assets, about a third of the amount held by Nomura Holdings Inc.’s retail segment. Morgan Stanley’s wealth business manages about $4 trillion of assets globally and employees about 16,000 financial advisers in the U.S.