William Fries, acclaimed stock picker at Thornburg Investment Management, will be transitioning out of his portfolio-management role over the course of next year.

Fries, 76, who is portfolio manager of the flagship Thornburg International Value Fund, will become a senior advisor to the firm and remain on the Thornburg investment team as an investment analyst and mentor, the company said Tuesday.

Also effective with the new year, Jason Brady, 41, head of global fixed income, will become president and CEO of Thornburg, while retaining his responsibilities as head of fixed income and as co-portfolio manager of the Thornburg Investment Income Builder Fund.

Current president and CEO Brian McMahon, 60,  will be named vice chairman and continue as chief investment officer and co-portfolio manager of the Income Builder and Global Opportunities funds.

McMahon joined the firm in 1984 as chief investment officer.

“We’re determined to perpetuate our unique process in terms of how we think, how we invest and how we’re structured,” said Garrett Thornburg, founder and chairman, in a statement.

“Promoting a respected senior executive like Jason who ‘gets it’ will continue that consistent approach,” he said.

Also announced Tuesday and effective immediately,  Di Zhou, 37, an associate portfolio manager, was promoted to managing director and co-portfolio manager of the International Value Fund.

Zhou is joining Fries and Lei "Rocky" Wang, 44,  as co-portfolio managers of the fund as well as other international strategies. Zhou joined Thornburg in 2010 as an equity research analyst.

“We expect this transition of responsibilities to be seamless based on the collaborative nature of [Thornburg’s] team approach,” McMahon said in a statement.

Fries has skippered International Value since it was introduced in 1998 and won Morningstar’s International-Stock Fund Manager of the Year award in 2003.

“Fries is a very senior and skilled manager, and that’s obviously significant for International Value,” said Morningstar analyst William Samuel Rocco.

Rocco declined to comment on what the change would do to the fund’s Bronze analyst rating, citing company policy.

“We’re taking a close look at the fund,” he said.

Founded in 1982 and headquartered in Santa Fe, New Mexico, Thornburg manages about $56 billion.