Robert Capaldi, who served as senior client strategist for BlackRock Inc. Chairman and Chief Executive Laurence Fink, has left the firm, a source familiar with the move said yesterday.

His departure on June 1 marks the fourth senior executive to leave BlackRock this month. With $3.7 trillion of assets under management, BlackRock is the world’s biggest fund manager.

Capaldi’s position in New York will not be filled, according to the source who declined to be identified.

Capaldi headed BlackRock’s US and Canadian institutional business until November 2010.

He joined BlackRock in 1997 from consulting firm RogersCasey, where he was director of fixed income research, according to a BlackRock biography.

A company spokeswoman declined to comment.

Capaldi is one of a number of executives to leave BlackRock during the past few weeks. Two weeks ago, the New York-based asset manager said Robert Doll, chief equity strategist at the firm, will retire at the end of the month.

On Wednesday, the firm said BlackRock founding partner Susan Wagner was retiring as vice chairman.

And on Thursday, Blackrock said portfolio manager Daniel Rice was leaving, citing the appearance of a potential conflict of interest involving his family business and holdings in the firm’s energy mutual funds, which he co-managed.