'She's Ready'

"She's been exposed to everything she could be exposed to at Fidelity," John Bonnanzio, editor of Fidelity Insight, a independent newsletter based in Wellesley, Mass., said in a telephone interview. "I'd have to say, yes, she's ready for this job."

Employees control 51 percent of the voting shares in Fidelity, and the Johnson family owns the other 49 percent. Ned and Abigail Johnson each hold at least 10 percent, according to regulatory filings.

Abigail Johnson ranked ninth in March on Forbes's list of billionaires whose fortunes came from private U.S. companies, with an estimated net worth of $10.3 billion.

"Abby will oversee all these corporate groups and will be involved in day-to-day activities," spokeswoman Anne Crowley said in a telephone interview. "Ned continues to be actively involved in running the company and doesn't have any plans to step aside from those roles."

All Businesses

Abigail Johnson's responsibilities will cover every major Fidelity business except Devonshire Investors, Crowley said. Devonshire, named for the Boston street where the firm is headquartered, manages investments for FMR LLC, Fidelity's corporate holding company, and its shareholders.

"I honestly think Ned will be more and more a listener, and not a dictator of his own demands," said Lowell, who is also chief strategist at Adviser Investment Management Inc. in Newton, Mass.

Abigail Johnson first interned at Fidelity in 1980, the summer before she enrolled at Hobart and William Smith Colleges in Geneva, New York, where she majored in art history. Like her father she has long guarded her privacy.

"We've been asked by her not to talk about her time here," art history professor Elena Ciletti said in 2004 when contacted by Bloomberg News.