The world's largest money manager said in a memo seen by Reuters that the shake-up in management is an effort to create an eventual succession plan for Fink and other leaders of the company who have been there for many years.
BlackRock manages $4.3 trillion in assets and is said to be shifting around 10 senior executives into new or expanded roles.
Rob Goldstein, a 20-year veteran at the company, will be taking over as chief operating officer on June 1. He replaces Charlie Hallac, who helped build BlackRock's Aladdin trading system and has been fighting colon cancer, as Hallac steps into the role of co-president.
The memo said that Hallac is at the office every day, even as he undergoes treatment for his cancer, and will take on the task of improving technology at the firm when he officially assumes the role of co-president.
Goldstein, the global head of the firm's institutional client business, will be replaced by Mark McCombe, chairman of BlackRock Asia Pacific. Goldstein and McCombe are among the leading candidates to succeed Fink.
Fink, 61, said in the memo that the changes are part of a larger strategy to periodically move leaders into new roles, exposing them to new environments and new geographic regions to make sure they are ready when they need to be.
Although BlackRock's sights are on the future, the company said neither Fink nor President Rob Kapito is going anywhere in the near future.