Marc Seidner is rejoining PIMCO 10 months after he left in a new role as chief investment officer for non-traditional strategies, spokeswoman Agnes Crane said.
He will also serve as head of portfolio management for the New York office.
Mr. Seidner is the latest person to return to PIMCO after the Sept. 26 departure of co-founder and CIO William H. Gross.
Last week, Pacific Investment Management Co. announced other key changes including that Nobel laureate Michael Spence was rejoining the firm as a consultant and Jeremie Banet would return would return as executive vice president and portfolio manager for real-return strategies.
The new hires are all part of a plan to bolster PIMCO's portfolio management efforts in an effort to stem redemptions from the firm, sources say. They say that PIMCO is expected to announce other hires in coming weeks and months.
Mr. Seidner is considered a protege of former PIMCO CEO Mohamed El-Erian. He left PIMCO in January, giving up his position as a senior portfolio manager following Mr. El-Erian's announcement that he was leaving PIMCO.
Mr. Seidner had worked for Mr. El-Erian at the Harvard Management Co. and in 2009 joined him at PIMCO.
Mr. El-Erian, who had shared the co-CIO spot with Mr. Gross, left PIMCO after clashes with Mr. Gross, sources say.
Mr. Seidner, who will be based in New York, will be one of six specialized investment chiefs who report to group CIO Dan Ivascyn, a PIMCO news release said. Mr. Ivascyn was named group CIO following Mr. Gross' departure.