Finance chiefs took longer than other executives to drop out, and did so with little public acknowledgment.
A spokesman for JPMorgan confirmed chief executive Jamie Dimon will no longer attend, but declined to say why. People familiar with the matter who spoke on the condition of anonymity to discuss sensitive details said Larry Fink and Stephen Schwarzman, the heads of BlackRock and Blackstone, also backed out.
Private equity firm KKR & Co. said Monday its co-president, Joseph Bae, and Gen. David Petraeus, chairman of the KKR Global Institute, were "not participating" in the conference. The event's website had listed both men as speakers.
Companies and executives in other industries also appeared to distance themselves from the Saudis Monday. Diane Greene, the head of Google's cloud-computing business, will no longer attend the conference, a spokeswoman said. Ford Motor Executive Chairman Bill Ford won't attend because of a scheduling conflict, a spokeswoman said.
Two more Washington lobbying firms also dropped their representation of Saudi Arabia on Monday. The Glover Park Group notified the Saudi Embassy that it was canceling its two-year-old contract, according to a person with knowledge of the move who spoke on the condition of anonymity to describe private conversations.
The consulting firm, established by Democratic political veterans, had been receiving a fee of US$150,000 a month, according to disclosure reports filed with the Justice Department.
The GOP-founded lobbying powerhouse BGR Group, which had an US$80,000-a-month contract with the Saudi government, announced it was also dropping the kingdom as a client.
"BGR is no longer working for Saudi Arabia," said Jeffrey H. Birnbaum, president of BGR's public relations division.
Saudi Arabia plowed US$27 million into lobbying in Washington last year, making it one of the highest-spending countries seeking to influence US policy, according to public records.
And Endeavor, the Hollywood talent agency led by Ari Emanuel, appeared to be ready to unwind a significant deal with the Saudi monarchy.
Last spring Endeavor accepted a US$400m investment from the country's Public Investment Fund in exchange for an undisclosed minority stake in the company.
On Monday, industry publication the Hollywood Reporter, citing anonymous sources, said Endeavor was seeking to give back the money and revoke the stake. An Endeavor spokesman declined to comment on the report.
JPMorgan is among the companies with the most at stake. The bank has been one of the leading managers of Saudi Arabia's large bond sales in recent years, including a sale this year that raised US$11 billion for the kingdom.
The bank is also among the advisers Saudi Arabia hired to help sell pieces of the kingdom's state-owned oil business. The centerpiece of that effort is the planned, though long delayed, public offering of part of Aramco.
JPMorgan and the other banks hired for that IPO could stand to share billions of dollars in fees if that sale goes ahead, market experts say. Stock exchanges around the world also have jockeyed to be chosen for that share listing.
Asset managers including BlackRock and Blackstone, which invest money for wealthy countries and individuals, also have close ties to the kingdom. Saudi Arabia's sovereign wealth fund agreed to contribute US$20b to a Blackstone fund designed to invest in US infrastructure projects.
Before backing out of the Saudi event, Dimon, Fink and Schwarzman spoke with each other this weekend to decide on the best course of action, people familiar with the matter said, confirming a report in the New York Times.
They discussed asking the Saudis to postpone the event, and had their staff contact Treasury Department officials to suggest that Secretary Steven Mnuchin also ask the Saudis to postpone the conference until more facts about Khashoggi's disappearance are made public, the people familiar with the matter said.
Mnuchin said last week that he planned to attend, though a spokesman said Sunday that Treasury "will evaluate the information that comes out this week."