Greg Abel has completed his first 100 days as chief executive officer of Berkshire Hathaway, during which he has begun reviewing the conglomerate's existing business operations and investment portfolio.

Abel, who succeeded Warren Buffett as CEO, is conducting assessments of businesses and investments that were established during Buffett's decades-long leadership of the company. The review represents one of Abel's first major initiatives since taking the helm of the Omaha-based holding company.

The transition marks a significant shift for Berkshire Hathaway, which operated under Buffett's leadership for more than five decades. Abel previously served as vice chairman for non-insurance operations before being elevated to the top position.

Berkshire Hathaway owns dozens of subsidiaries across various industries, including insurance, energy, manufacturing, and retail, along with significant equity stakes in public companies. The company's investment portfolio and operating businesses were largely shaped by Buffett's investment philosophy and acquisition strategy over the years.