Both companies declined to comment when contacted by Reuters.
The three-day conference, scheduled to start on October 23, is the centerpiece of the crown prince's plan to diversify the country's oil-dependent economy, reform its deeply traditional society and revamp its worldwide image.
Khashoggi was a critic of the regime in effect led by the Bin Salman since his father appointed him crown prince in June 2017.
Khashoggi, a Saudi national and United States resident who became increasingly critical of powerful Crown Prince Mohammed bin Salman, has not been seen since he walked into the Saudi consulate in Istanbul to sort out marriage paperwork on October 2. This created a major diplomatic crisis for the kingdom, with mounting evidence that the Saudis were involved fueling a growing outcry from foreign governments, USA lawmakers and the Trump administration. Turkey had publicly scolded the Saudi government for refusing repeated requests to search the consulate, where Turkish investigators believe Khashoggi was killed and dismembered by Saudi agents.
Riyadh has strenuously denied these reports.
A statement issued by the Ministry of Foreign Affairs and International Cooperation in the Comoros said the government of the Comoros is following with concern the repercussions of the disappearance of Khashoggi in Turkey and frenzied media campaigns. He visited the Saudi Consulate on October 2 to obtain documents related to his upcoming wedding, but he was never seen leaving.
"I don't think any of our government officials should be going and pretending it's business as usual until we know what's happened here", said Rubio, a Florida representative.
Oil edges further above $80 but weaker demand view weighs
West Texas Intermediate Crude was trading up 0.31 per cent at $71.19, down more than $3 per barrel from last Friday. Declining equities amid wider risk-off investor sentiment had pressured oil on Thursday.
A column published by the general manager of the Saudi-owned Al-Arabiya satellite news network suggested Saudi Arabia could use its oil production as a weapon and Saudi arms purchases from the U.S. and other trade could also be at risk. "He's made that his signature", he said of the crown prince, who is 33.
Mr Trump has sent US Secretary of State Mike Pompeo to Saudi Arabia to meet the King.
Trump told reporters he'd spoken to the Saudi king, who assured him they had not ordered Khashoggi's extermination, and suggested helpfully it may have been the work of a "rogue killer".
President Trump has warned that Saudi Arabia would face "severe punishment" if it was found to have killed Khashoggi. Later that same day, however, the Saudi embassy in Washington tweeted a clarification that pretty much dismissed the tone of the official source's warning reported by the SPA. Ford Motor Co said Chairman Bill Ford has canceled his trip to the Middle East, which included an appearance at the Saudi investment conference. The Arab News published a front-page editorial by Dubai-based real-estate tycoon Khalaf al-Habtoor that urged Gulf Arab nations to boycott worldwide firms now backing out of the investment conference later this month.
He also said Mnuchin should skip the Saudi conference.
Lagarde has said she will attend because she has to conduct the business of the International Monetary Fund "in all corners of the world".
He said Bangladesh is following the news of the disappearance.
That fear appeared to spread on Monday to Japan's SoftBank, which has invested large sums of Saudi money.