In an analysis of public records and Clinton Foundation data, The Washington Post found that there was an overlap of Bill and Hillary Clinton's charitable work and their growing personal wealth. The Post's Rosalind S. Helderman breaks it down. (Alice Li/The Washington Post)

Bill Clinton was paid at least $26 million in speaking fees by companies and organizations that are also major donors to the foundation he created after leaving the White House, according to a Washington Post analysis of public records and foundation data.

The amount, about one-quarter of Clinton’s overall speaking income between 2001 and 2013, demonstrates how closely intertwined Bill and Hillary Clinton’s charitable work has become with their growing personal wealth.

The Clintons’ relationships with major funders present an unusual political challenge for Hillary Rodham Clinton. Now that she has formally entered the presidential race, the family may face political pressure and some legal requirements to provide further details of their personal finances and those of the foundation, giving voters a clearer view of the global network of patrons that have supported the Clintons and their work over the past 15 years.

The multiple avenues through which the Clintons and their causes have accepted financial support have provided a variety of ways for wealthy interests in the United States and abroad to build friendly relations with a potential future president. The flow of money also gives political opponents an opportunity to argue that Hillary Clinton would face potential conflicts of interest should she win the White House. Though she did not begin delivering paid speeches or join the foundation until 2013, upon ending her tenure as secretary of state, the proceeds from her husband’s work benefited them both.

Bill Clinton was paid more than $100 million for speeches between 2001 and 2013, according to federal financial disclosure forms filed by Hillary Clinton during her years as a senator and as secretary of state.

At a Council on Foreign Relations event on women’s rights in New York City, Chelsea Clinton, vice chair of the Clinton Foundation, fielded questions about recent controversies over foreign donations to the foundation. (Council on Foreign Relations)

A spokesman for Bill Clinton declined to comment on the overlap between speech sponsors and foundation donors, saying only that the former president’s speaking schedule has been largely consistent since he left the White House.

Craig Minassian, a spokesman for the foundation, said it makes sense that supporters of the foundation would also be eager to hear from the former president.

“It’s not surprising that organizations who believe strongly in the Clinton Foundation’s mission and are impressed by its results are genuinely interested in President Clinton’s perspective,” Min­assian said. “The president often says the foundation is his life today, and he welcomes any opportunity to educate people about it and encourage more people to work together to solve some of the most critical global challenges we all face.”

The Post analysis shows that, among the approximately 420 organizations that paid Bill Clinton to speak during those years, 67 were also foundation donors that each gave the charity at least $10,000.

Many of those funders were major financial institutions that are viewed suspiciously by liberals whom Clinton has been courting as she seeks to secure the Democratic nomination — and avoid a vigorous primary challenge from the populist left.

Four major financial firms — Goldman Sachs, Barclays Capital, Deutsche Bank and Citigroup — collectively have given between $2.75 million and $11.5 million to the charity, which is now called the Bill, Hillary and Chelsea Clinton Foundation. Between 2001 and 2013, their combined speech payments to Bill Clinton came to more than $3 million.

The Post analysis also revealed aspects of Bill Clinton’s paid speaking career during Hillary Clinton’s tenure at the State Department that were not clear from her public filings.

Those included:

●The role played by dozens of companies and organizations, some of them associated with foreign governments or with interests before the U.S. government, in serving as secondary hosts for a number of the speeches. In her filings, Hillary Clinton typically disclosed only the primary sponsor of each speech.

One such “sub-sponsor” was Boeing, a major government contractor whose interests Hillary Clinton promoted in her official duties at the State Department.

●Four speeches delivered by Bill Clinton did not appear in Hillary Clinton’s filings. One such speech was a 2012 address to an annual meeting of the Carlyle Group, a politically connected private-equity firm.

A spokesman for Bill Clinton’s office said the former president at times spoke to benefit the foundation, which would not trigger a disclosure requirement for Hillary Clinton. None of the four speech sponsors are listed as foundation donors. The spokesman said the proceeds were classified as non-tax-deductible revenue — not donations.

The Clintons’ finances have already become a political flash point with the much-anticipated release next month of a new book examining the foundation and the family’s personal wealth. The Clinton campaign has dismissed “Clinton Cash,” written by conservative author Peter Schweizer, as a partisan attack.

The Post received a copy of the manuscript after signing a non-disclosure agreement with publisher HarperCollins. This article is based on reporting and documents collected independently from Schweizer’s book.

The foundation itself has also emerged as an issue. In recent weeks, some Democrats have expressed anxiety about the foundation’s receipt of millions of dollars in donations from foreign governments while Hillary Clinton was secretary of state. Records show that the foundation accepted contributions from seven foreign governments during that time, including one donation that the foundation has acknowledged violated an ethics agreement with the Obama administration designed to limit new foreign-government donors.

Clinton aides have said the foundation goes beyond legal requirements and industry standards in its transparency. Its Web site lists donors and their contribution amounts, expressed in ranges.

It is not unusual for former presidents to boost their income through an active schedule of paid lectures; records show Bill Clinton has often shared the stage with former president George W. Bush or delivered speeches in front of groups that had previously hosted Bush or his father, former president George H.W. Bush.

Clinton has been in particular demand as a speaker because of his renowned oratory and growing popularity in post-presiden­tial life, partly based on the widely respected work of the foundation. Speech organizers, which have included universities, charities and major lecture series, report that the former president is a major draw and that he often boosts attendance for annual events.

What sets the Clintons apart is the vast reach of their donor network and the extent to which they have tapped it for the broad range of their personal, political and charitable work.

The Post’s analysis, based on foundation disclosures, State Department documents, financial filings and other records, shows that the lines between Clinton’s paid speeches and his work for the foundation often blurred as he traveled the world promoting the charity and reaping millions in payments.

Technology companies Microsoft and Cisco Systems, for instance, donated at least $1 million each to the foundation. The two companies paid Bill Clinton a total of $1.02 million in speaking fees for a series of lectures.

In September 2012, the Italian fitness equipment company Technogym paid Bill Clinton $500,000 for a speech in the northern Italian city of Cesena at a conference devoted to “creating a better and more sustainable world through people’s health,” according to financial disclosures and documents Bill Clinton’s office submitted to the State Department.

Technogym, which has also given between $25,000 and $50,000 to the foundation, reported in a news release that the speech came about in part because of the foundation’s work fighting childhood obesity.

Clinton spent much of his remarks discussing the work of the foundation to improve global health and comparing it to efforts by the company and its affiliated charity to promote the same ideas. “So I’m very interested in all these things that the Wellness Foundation and that this conference and that Technogym does — because we are trying to do this,” Clinton said, according to a YouTube video of his remarks.

Technogym did not respond to a request for comment.

The intermingling of foundation and paid work was also apparent earlier that year when Bill Clinton addressed an advertising festival in Cannes, France.

Grupo ABC, a major Brazilian advertising company, paid Bill Clinton $450,000 for the June 2012 appearance. Foundation records show that the firm has given the charity between $1.5 million and $6 million.

Excerpts from the event posted on YouTube show that Clinton was introduced with a video devoted to the work of the charity. “I personally believe that if the American people give you the honor of serving them, you should keep doing it after you leave office,” Clinton says in the video.

State Department records show that Bill Clinton gave a speech and participated in a moderated question-and-answer session in Cannes for 1,000 advertising employees and then attended a reception for 75 at a luxury hotel.

Grupo ABC spokesman Sergio Malbergier said the company has worked with a series of global charities and nongovernmental organizations as part of a belief in being a “socially responsible organization.” He said the company has supported the Clinton Foundation “because of the importance and effectiveness of its work.”

Bill Clinton was invited as a keynote speaker to help celebrate the company’s 10th anniversary, Malbergier said, because company leaders have found his vision “a great source of inspiration.”

A Clinton Foundation official said organizations that pay for the former president to speak are often interested in the work of the charity and request that Clinton address it in his remarks.

The Post analysis also found other previously unreported aspects of Bill Clinton’s speaking career.

While Hillary Clinton named the sponsoring organization for each of her husband’s speaking engagements, separate documents show that Bill Clinton’s office listed 97 additional sub-sponsors that had been proposed to help with these speaking events.

Bill Clinton disclosed the additional information as part of a voluntary ethics process undertaken when Hillary Clinton became secretary of state. He agreed to seek State Department approval of his paid speaking engagements to avoid conflicts of interest for his wife.

The correspondence between Bill Clinton’s office and the State Department was released in July after the conservative group Judicial Watch sought the records, ultimately filing suit to force their release.

Hillary Clinton was not obligated to disclose the sub-sponsors in her annual filings. The State Department’s correspondence with Bill Clinton’s office provides the only indication of the additional interests that helped support the former president’s paid speaking career.

In 2010, for instance, Hillary Clinton disclosed that her husband had been paid $250,000 to address the American Chamber of Commerce in Egypt.

But Bill Clinton’s office alerted the State Department that other sponsors for the event were proposed to include Etisalat, a large Middle Eastern telecommunications company whose majority owner is the government of the United Arab Emirates.

Likewise, in 2012, Hillary Clinton’s disclosures show, Bill Clinton was paid $250,000 for a Boston speech to the Global Business Travel Association.

But the documents filed by Bill Clinton’s office show that a proposed sub-sponsor was the aircraft manufacturing giant Boeing. During a 2009 trip to Russia, Hillary Clinton made a personal pitch for a state-owned airline to buy Boeing jets.

Gordon Johndroe, a Boeing spokesman, said the company has sponsored the major travel event for several years, regardless of its invited speakers.

Some sub-sponsors also were foundation donors, including Boeing, which has given more than $1 million to the charity.

In addition, the Post analysis found that Bill Clinton delivered some paid speeches during Hillary Clinton’s tenure at the State Department that were not publicly disclosed.

By law, Cabinet members and lawmakers must disclose speeches for which their spouses were paid at least $200. And the foundation has voluntarily updated its donor list on its Web site each year since 2008.

But four speeches were not disclosed in either fashion.

A spokesman for Bill Clinton’s office said that the former president “complied with disclosure requirements in every case” and that any speech fee not disclosed as personal income by Hillary Clinton went to the foundation.

But he said those fees were not tax deductible for the sponsoring organization and thus were not considered donations to the charity. He said they were included in the revenue figure provided in the foundation’s tax filings.

The examples The Post found were:

●A speech delivered in October 2011 in front of 9,000 at the University of Rochester’s Meliora Weekend, the school’s annual reunion and parents weekend. University officials confirmed that he delivered the speech for a fee, which they would not disclose.

●An appearance at the Minneapolis Heart Institute’s annual gala, also in October 2011. Event organizers said Clinton was supposed to attend in person but appeared via video link after a snowstorm confined him to Washington. They said a $25,000 fee was paid for his appearance at the event that, according to State Department records, was also sponsored by the Land O’Lakes dairy company.

“We wanted a speaker who could speak personally about heart disease and heart treatment,” said Minneapolis Heart Institute spokeswoman Melissa Hanson. “In addition, we wanted someone with first-class credibility. President Clinton was a natural fit.”

●A September 2012 question-and-answer session at the annual investors meeting of the politically connected private-equity company the Carlyle Group. A spokesman would not comment on Bill Clinton’s fee. According to Politico, Hillary Clinton was paid to appear at the same event a year later, after she stepped down as secretary of state.

●Bill Clinton’s participation as the guest of honor at a dinner in Limerick, Ireland, in November 2012 at which scholarships were awarded to Irish students. A spokeswoman for the organizing group confirmed Clinton traveled to Ireland to take part in the dinner.