Mitsubishi UFJ Financial Group Inc. said Oct. 13 that it has bought a 21 percent stake on a fully diluted basis in U.S. investment bank Morgan Stanley for $9 billion, after making revisions to the terms of the acquisition.

The new terms allowed the largest Japanese banking group to make the entire investment in the purchase of only preferred shares in Morgan Stanley, compared with a previous agreement that called for the purchase of preferred and common shares.

MUFG renegotiated the terms of the deal, which helped save Morgan from going bankrupt, on the back of a plunge in the share price of the major U.S. brokerage. The stock plunge could have caused huge unrealized losses at MUFG, if it implemented its planned investment based on the initial deal.