Mr. El-Erian's ubiquity in the media – including writing for the Financial Times – was speculated to be a possible source of tension by one industry consultant. However, people familiar with the company said Mr. Gross approves of – and practices – the art of promoting the company's ideas to a broad range of potential customers.
Though Mr. Gross has emphasized his intention to stay as chief investment officer for the foreseeable future, there is still some doubt over his successor given Mr. El-Erian's exit.
Pimco is looking to bring in additional top managers from outside the company, said people familiar with the matter, though others believe the successor will come from within.
(Read more: El-Erian's exit adds to risks at Pimco)
Promoted to deputy chief investment officers in the reshuffle on Tuesday were Andrew Balls, head of European portfolio management, a former Financial Times journalist and brother of the U.K.'s shadow chancellor Ed Balls; and Daniel Ivascyn, the lead portfolio manager for Pimco's alternative investment strategies.
Mr Ivascyn won the title of fund manager of the year for 2013 alongside his colleague Alfred Murata. The accolade, administered by Morningstar, is seen as one of the industry's top awards. Mr Balls has also "established himself in a big way," according to one insider.
—By Tom Braithwaite of the Financial Times