Long-time Morgan Stanley veteran Michael Durbin on Wednesday was named president of Fidelity Institutional Wealth Services, the RIA custodian division of Fidelity Investments. He succeeds John "Jack" Callahan, who led the division since October 2006.

Durbin comes to Fidelity after 18 years at Morgan Stanley, including his most recent job as chief operating officer of the global wealth management group's national sales division where he was in charge of marketing, business development and investment strategy for the company's 8,000 U.S.-based financial advisors.

Durbin starts his new job in early 2009 and will report to Michael Clark, president of Fidelity Institutional Products Group. Fidelity Institutional Wealth Services custodies more than $335 billion in assets for 3,500 clients among RIAs, trust institutions and third-party administrators.

Callahan will oversee development of a new sales organization at Fidelity Personal and Workplace Investing, which handles the company's workplace retirement services (defined benefit plans, 401(k)s, and human resources) and retail brokerage businesses. In prior roles with Fidelity, Callahan was president of the company's defined-contribution plan business and was executive vice president in its human resources service.