Though Fink has no imminent plans to retire, he along with President Robert Kapito has been training these candidates for "The Great Race" - to choose the successor - in what Fink calls is the "No. 1 priority", the report said, citing an interview with the CEO.

The five contenders are Mark Wiedman, who runs the global commercial business; Chief Operating Officer Rob Goldstein; and Chief Financial Officer Martin Small along with Rachel Lord, head of the Asia Pacific business, and Salim Ramji, the head of ETFs and indexing products, the report said.

Fink told the newspaper he hoped to build camaraderie among the five, and not competition, so they will keep working together.

Fink did not give a definite timing as to when he would retire but said he "would prefer to not be at BlackRock in his late 70s", the report said, adding there was a chance he could stay on as chairman after stepping down as CEO.

BlackRock did not immediately respond to Reuters' request for comment.

Last year, Activist hedge fund Bluebell Capital Partners took aim at BlackRock and wanted to replace Fink as the CEO, calling the world's largest asset manager inconsistent in its focus on environmental, social and corporate governance (ESG) issues. BlackRock said it plans no major changes to the way it engages with companies.

(Reporting by Baranjot Kaur in Bengaluru; Editing by David Gregorio)