Morgan Stanley, a multinational financial services corporation, is currently in the middle of leadership transition as the company announced the appointment of its investment banking chief, Cohm Kelleher, as its sole president. The appointment came after current wealth-management division president Greg Fleming decided to leave the firm to pursue other opportunities.

Both Kelleher and Fleming had been seen as potential successors to Morgan Stanley CEO James Gorman. Unfortunately, Fleming is leaving the company, making Kelleher the sole president of the firm. Previously the president of the company's institutional-banking and trade division, Kelleher will now assume a huge role as he takeovers Fleming's responsibilities and oversee the firm's wealth-management division, which is one of the key sectors in Morgan Stanley, Business Insider noted.

"I am delighted to announce that Colm Kelleher has been named President of Morgan Stanley," CEO James Gorman said in a memo to Morgan Stanley employees on Wednesday. "Greg Fleming has decided to leave the Firm to pursue other opportunities."

"For the last five years, he [Kelleher] has led our ISG business, navigating challenging markets and adapting to a new regulatory environment while maintaining our world class equities and banking franchises," Gorman added. "I very much look forward to working with Colm as my partner in leading the Firm over the next several years."

After joining the firm in 1989, Kelleher bravely survived several challenges and navigated changes in the company's senior ranks. For 15 years, he supervised Morgan Stanley's fixed-income division. He had also directed the global-capital markets business before serving as CFO and co-head of corporate strategy during the tough years of the financial crisis. As of late, Kelleher is overseeing a retrenchment of the firm's fixed-income trading business, with 1,200 jobs set to be laid off worldwide.

Fleming, on the other hand, was once seen as Gorman's successor. Unfortunately, he was outshined during the management reshuffle in October, which prompted his departure. According to Reuters, he had hoped to reshape the firm's wealth management's workforce in the coming years by including more women and millennial advisers. Thus, he invested more in the firm's technology to attract them.

Wall Street power brokers also saw Fleming's potential to be the next CEO. However, an insider said that he refused Morgan Stanley's offer to stay and told the company about his exit this week. And as for Gorman, the company's 57-year-old CEO is also in no hurry to leave as he intends to stay as chairman and CEO for five to seven years, Bloomberg reported.

Meanwhile, there are also no guarantees if Kelleher will eventually replace Gorman since there are other potential CEO successors. The list include Chief Financial Officer Jon Pruzan, head of trading Ted Pick and Shelley O'Connor, a veteran of the wealth management business who was promoted as co-head of the division on Wednesday along with Andy Saperstein.