In the latest shakeup at a major brokerage firm, John Thiel will step down as head of Merrill Lynch Wealth Management, a role he's held since 2011, according to a company statement.

Andy Sieg, head of Merrill’s Global Wealth and Retirement Solutions unit, will succeed Thiel on Jan. 1. Sieg, 49, joined Merrill as an analyst in 1992. He left in 2005 to join Citigroup Global Wealth Management, then rejoined Merrill in 2009.

Thiel, 56, wanted to step away from the day-to-day running of the business, according to a person familiar with the matter. He will remain with the company in an advisory role as vice chairman of Bank of America's Global Wealth and Investment Management unit, which includes Merrill Lynch and U.S. Trust. Earlier this year, Greg Fleming left Morgan Stanley, where he had served as president of the company's wealth management unit, and John Taft retired as CEO of RBC Wealth Management-U.S.

John Thiel, left, will be replaced by Andy Sieg as head of Merrill Lynch Wealth Management on Jan. 1.

At Merrill, Sieg helped oversee the development of Merrill Lynch One, an adviser desktop platform that replaced five older ones, and which represented a major technology upgrade at the firm. Merrill One took three years to develop.

Sieg "has proven to be both a dynamic leader and accomplished at strategy execution," says Terry Laughlin, Bank of America vice chairman and head of Global Wealth and Investment Management. "He is ideally suited to lead Merrill Lynch on the next phase of its journey," Laughlin adds in a statement.

With regulatory and technological changes remaking the industry, Sieg may have his work cut out for him. When he takes the helm, the firm will be preparing to implement the Department of Labor's fiduciary rule, set to go into effect in stages beginning in April. The wirehouse has been emphasizing goals-based wealth management for years, and sees itself as well-positioned for the regulation.

Robo advisors have also been remaking parts of the business. Earlier this week, Merrill parent Bank of America unveiled plans to launch Merrill Edge Guided Investing, an online service and app, in early 2017.

A replacement for Sieg has not been chosen, a spokeswoman says.

In his new role, Thiel will advise Laughlin as well as the firm's leadership teams on goals-based wealth management and regulatory matters, according to the company.