Morgan Stanley’s James Gorman plans to step down as chief executive officer in the next 12 months and assume the role of executive chairman.

“It is the board’s and my expectation that it will occur at some point in the next 12 months,” Gorman, 64, said Friday at the firm’s annual meeting. “That is the current expectation in the absence of a major change in the external environment.”

Gorman, who became CEO at the beginning of 2010, said in January that there are three finalists to take over as CEO when he leaves. Though he didn’t name his likely successors, Ted Pick and Andy Saperstein, the New York-based firm’s co-presidents, have been in the running alongside investment-management chief Dan Simkowitz.

Gorman said Friday that he will serve as executive chairman “for a period of time” after leaving the CEO post.

“We believe this structure will ensure the continued stability of Morgan Stanley while at the same time positioning it for a decade of exciting growth under new leadership,” he said.

The Australian-born Gorman has been one of the longest-serving Wall Street leaders. His time as CEO has been marked by a major strategic overhaul of the firm that’s been accelerated by two of the largest deals struck by one of the big US banks in the years after the 2008 financial crisis.

Those transactions — the acquisitions of E*Trade Financial Corp. and Eaton Vance Corp. — and the bank’s growing reliance on a dual engine of the investment bank and its giant wealth-management business delivering growth has made the company’s stock one of the best performers among peers in the past decade.