David H. Komansky, the former chairman and chief executive officer of Merrill Lynch, who helped build the company into a global financial behemoth, died Sept. 27 at New York Presbyterian Hospital in Manhattan. He was 82.

A postal worker’s son who grew up in the Bronx and later dropped out of college, Mr. Komansky brought worldwide ambitions to his tenure as chief executive of the firm from 1996 to 2003. He bought businesses in the United Kingdom and invested in operations in Europe, Asia and Australia. In 1995, as Merrill’s president, he negotiated the $810 million acquisition of Britain’s largest independent stockbroker, Smith New Court. In 1997, Mr. Komansky oversaw Merrill Lynch’s acquisition of Mercury Asset Management of Britain, one of Europe’s largest investment firms, for about $5.3 billion. He also struck a deal with HSBC to provide online banking and investment services, which have since become an everyday offering from banks.

“When I would visit him in the office, I always loved coming down to the lobby with him,” Mr. Komansky’s daughter Elyssa Williams wrote to The New York Times in an email. “He knew who every single person in the building was, and would call them by name.”