Fidelity Investments’ longtime chairman Edward “Ned” Johnson is retiring, completing the transfer of the company to his daughter Abigail Johnson.

Fidelity operates a large campus in Research Triangle Park.

Abigail Johnson is taking over as chairwoman, the company said in a memo Monday. She is already Fidelity’s CEO, and will hold both positions. She joined the company in 1988 as an equity analyst.

Ned Johnson became CEO of Fidelity in the mid-1970s and led the Boston company through a period of growth fueled in part by the growing popularity of 401(k)s and other retirement accounts. The expansion made Ned and Abigail Johnson both billionaires, and made Fidelity one of the largest asset managers in the country.

“I never felt more confident about Fidelity’s future than I do now,” he said in the memo.

Ned Johnson, 86, will become “chairman emeritus” and will periodically meet with the company’s board of directors.

The promotion of Abigail Johnson was expected, as the Johnsons have held tight control over the privately held company for decades. Ned Johnson became chairman and CEO of Fidelity after his father stepped down from the company.

The company has some 40,000 employees. It services more than 25 million customers and has more than $2 trillion under management, according to figures from June 2016 published at the corporate website.