Morgan Stanley ’s number two executive Colm Kelleher is retiring, the Wall Street Journal reports, opening a seat whose filling will signal the Wall Street firm’s likely heir apparent.

Kelleher, who joined Morgan Stanley in 1989, is older than chief executive James Gorman and was not seen as a likely candidate to succeed him. But as the firm’s chief operating officer and president, he has overseen the day-to-day of its dramatic restructuring over the past decade from a error-prone trading shop to a stabler financial-services giant.