DUBAI/LONDON (Reuters) - U.S. Treasury Secretary Steven Mnuchin and Wall Street bankers will show up at an elite Saudi investment conference this month despite a growing exodus of top media companies and business leaders after the disappearance of a Saudi journalist.

United States Secretary of the Treasury Steven Mnuchin speaks during an interview with Reuters at the International Monetary Fund - World Bank Annual Meeting 2018 in Nusa Dua, Bali, Indonesia, October 12, 2018. REUTERS/Johannes P. Christo

Mnuchin’s plan to attend the high-profile Future Investment Initiative conference in Riyadh follows U.S. President Donald Trump’s comments that he saw no reason to block Saudi Arabian investments in the United States despite concern over the welfare of Jamal Khashoggi.

“I am planning on going at this point. If more information comes out and changes, we can look at that, but I am planning on going,” Mnuchin said in an interview with CNBC on Friday.

In a letter to Trump, the leaders of the U.S. House of Representatives Foreign Affairs Committee said Mnuchin should cancel plans to attend the conference unless Saudi Arabia fully discloses what it knows about Khashoggi’s disappearance.

“We urge you to use all pressure necessary to encourage greater Saudi cooperation in the investigation into this incident,” said the committee’s chairman, Republican Ed Royce, and its top Democrat, Eliot Engel.

Pressure has mounted on U.S. ally Saudi Arabia since Khashoggi, a critic of Saudi policies, went missing. He was last seen entering the Saudi consulate in Istanbul on Oct. 2.

Turkish officials have said Khashoggi was murdered inside the consulate. Riyadh has said the claims are baseless.

CNN, the Financial Times, the New York Times, CNBC and Bloomberg, as well as reporters and editors from the Economist, said they were no longer participating in the conference, which relies heavily on journalists to moderate top sessions.

CNBC and Bloomberg, along with Fox Business Network, were among media partners with a big role at the event, which begins on Oct. 23.

Uber Technologies Inc [UBER.UL] Chief Executive Officer Dara Khosrowshahi, U.S. mass media conglomerate Viacom Inc CEO Bob Bakish and billionaire Steve Case, one of the founders of AOL, said they were no longer going. Entrepreneur Arianna Huffington will also not participate and has resigned from the conference advisory board, her company Thrive Global PR said.

The absence of media and technology executives is likely to cast a shadow over the three-day conference, known as “Davos in the desert”, which has become the biggest show for investors to promote Saudi Crown Prince Mohammed bin Salman’s reform vision.

It has attracted some of the world’s business elite, including Wall Street’s top bosses and executives from multinational media, technology and financial services companies.

On Friday, conference organizers removed all the names of attendees from its website as the number of cancellations grew.

“Whilst it is disappointing that some speakers and partners have pulled out, we are looking forward to welcoming thousands of speakers, moderators and guests from all over the world to Riyadh,” a Future Investment Initiative spokesperson said.

World Bank President Jim Yong Kim, listed as a speaker, will not go to Riyadh due to a scheduling conflict, a World Bank official said on Friday.

Asked about business leaders’ doubts about the conference, a Saudi diplomatic source said late on Thursday that he hoped a joint Turkish-Saudi investigation into the affair could reach a conclusion before the event began.

However, the fallout over Khashoggi’s welfare shows signs of extending beyond conference participation.

British billionaire Richard Branson said his Virgin Group would suspend discussions with Saudi Arabia’s Public Investment Fund over a planned $1 billion investment in the group’s space ventures.

On Wednesday, former U.S. Energy Secretary Ernest Moniz said he had suspended his role on the board of Saudi Arabia’s planned mega business zone NEOM - another of Prince Mohammed’s large projects - until more is known about what happened to Khashoggi.

TOP GUNS

While many media and technology executives have abandoned the conference, the financial industry showed no signs of doing so.

None of the financial firms whose senior executives were scheduled to speak said they had made any changes to those plans when contacted by Reuters.

Europe’s biggest bank, HSBC, declined to comment on whether CEO John Flint is still attending. HSBC is a ‘strategic partner’ of the event, along with Credit Suisse, whose CEO Tidjane Thiam is still planning to attend, according to a source familiar with the matter.

Bill Winters, CEO of Asia, Africa and Middle East-focused bank Standard Chartered is likewise still planning to go, a spokeswoman at the lender told Reuters. JPMorgan Chase & Co CEO Jamie Dimon was scheduled to speak, as was Mastercard Inc CEO Ajay Banga. Representatives for those companies, as well as Bank of America, Citigroup, Goldman Sachs and Morgan Stanley did not respond to requests for comment.

Siemens AG said CEO Joe Kaeser still planned to attend.

High-profile investors also steered clear of announcing plans to abandon the conference. BlackRock, the world’s largest asset manager, said it was “closely monitoring the situation.”

Private equity company Blackstone did not immediately respond to a request for comment on whether CEO Stephen Schwarzman would still speak at the event.

A spokesman for the London Stock Exchange, whose CEO David Schwimmer is also a speaker, declined to comment. The exchange has been working for years to attract the listing of Saudi state oil major Aramco.

The City of London, Britain’s financial district and one of the main lobbyists for the country’s finance sector, said it is urgently seeking more information on Khashoggi. Its leader Catherine McGuinness is due to attend the conference.