(Reuters) - BlackRock Inc
Novick, 59, will continue in her current role until her successor is chosen, after which, she will serve as a senior adviser to the company, according to the memo.
She will also assist in conducting internal and external searches to find her successor.
"Much of the post-financial crisis policy work that Barbara led is largely implemented, and she has greatly enhanced our stewardship practices, including our commitment to transparency", Chief Executive Officer Larry Fink said in the memo.
Less than half of BlackRock's original slate of eight co-founders will remain at the firm once Novick leaves.
She has been vocal on issues, including CEOs serving on other companies' boards.
"It sounds fine to sit on multiple boards, but what happens when something goes wrong at a company?" she said in an interview last year.
The news of Novick's departure comes months after BlackRock announced the exit of Mark Wiseman, global head of active equities, following a violation of the company's "relationships at work policy".
(Reporting by Abhishek Manikandan and C Nivedita in Bengaluru; Editing by Anil D'Silva, Vinay Dwivedi and Shinjini Ganguli)