Blackstone has hired a managing director to join its team advising a rapidly growing pool of wealthy investors who back vehicles such as real estate and credit funds run by the world's biggest private-equity manager.

David Stubbs is joining Blackstone as a senior investment strategist in its private wealth solutions group, reporting to Joe Zidle, the team's chief investment strategist, according to two people familiar with the matter. The group caters to high-net-worth investors, a key market for the New York firm.