Mrs. Clinton has been fairly explicit that she will keep Mr. Clinton busy if she becomes president, saying he could become “ambassador to the world” — with the William J. Clinton Foundation and missions to improve ties with other nations and tackle foreign policy hot spots.

A non-earning Mr. Clinton would be a big change for the couple, but it would also reduce apparent or actual conflicts of interest if she was president and he had decided instead to remain in a money-making position.

Mr. Clinton gives dozens of paid speeches a year, mostly to corporations and philanthropic groups in North America and Europe, typically earning from $100,000 to $200,000 per speech. He earned more than $30 million in speaking fees from 2001 to 2005, according to his wife’s Senate  ethics reports.

He has been an adviser to a family of funds run by the Yucaipa Companies, a California private equity firm controlled by a friend, the billionaire Ronald W. Burkle. Under terms described by Mr. Clinton’s aides and Mr. Burkle, Mr. Clinton stands to earn tens of millions of dollars from the arrangement over time, depending on the funds’ growth.