A security official holds barriers during the arrival of Saudi officials at Saudi Arabia's consulate in Istanbul, Turkey, on Oct. 15, 2018. (MURAD SEZER/Reuters)

A string of high-profile finance executives followed technology and media leaders in pulling out of a Saudi investment conference scheduled for late this month, potentially risking a lucrative role in the kingdom’s plans for a historic opening of its economy.

The heads of JPMorgan Chase and the asset management giants BlackRock and Blackstone Group dropped out of the conference amid reports that Saudi agents killed dissident journalist and Washington Post contributor Jamal Khashoggi.

The defections could jeopardize the large fees global banks and investment firms have been earning from the kingdom — and the promise of even bigger business if Saudi Arabia makes good on plans to privatize its oil industry and boost foreign investment in a variety of sectors.

“Saudi Arabia is the biggest economy of the region, and the current reform plans rely on opening it further to private investment,” said Karen Young, a political economist who studies the Gulf states.

“This is a market opportunity similar to the liberalization of a country like Poland in post-socialist Eastern Europe in the early 1990s. Those banks and firms that reject the [conference] invitation now may find doors closed to them in the future,” Young said.

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 $150,000 a month, according to disclosure reports filed with the Justice Department.

The GOP-founded lobbying powerhouse BGR Group, which had an $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 $27 million into lobbying in Washington last year, making it one of the highest-spending countries seeking to influence U.S. 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 $400 million 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 $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 $20 billion to a Blackstone fund designed to invest in U.S. 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.”

Steven Zeitchik in New York and Tom Hamburger contributed to this report.