In response to a shareholder asking whether the company would invest in bitcoin, Fink told its annual meeting: "The firm has monitored the evolution of crypto assets. We are studying what it means, the infrastructure, the regulatory landscape."

BlackRock, the world's largest asset manager running roughly $9 trillion, is a long-term investor, Fink said. And crypto currencies could potentially play a role in long-term investing as an asset class similar to gold.

For now, it is too early to determine whether cryptocurrencies are "just a speculative trading tool" he said. He also noted that broker dealers are the ones making the most money from the volatility of many cryptocurrencies and their wide bid-ask spreads.

Earlier in the meeting, BlackRock said all of its 16 director nominees were elected with a majority of shareholder votes cast. It also said that executive pay had been backed by 93% of shareholder votes.

A shareholder resolution to convert the company into a public benefit corporation - with the aim of putting all stakeholders on equal footing with shareholders - was rejected, receiving only 2.3% of the vote. The vote was in line with what similar proposals have received this year at other big U.S. companies and financial firms.

(Reporting by Kate Duguid and Ross Kerber; editing by Chizu Nomiyama and Philippa Fletcher)

By Kate Duguid and Ross Kerber