0111 GMT January 20, 2019
Among the latest, the government of New Zealand said it would not attend, as did the head of the main banking unit of Japanese financial group MUFG.
Saudi Arabia will host the key investment summit on Tuesday, overshadowed by the killing of critic Khashoggi that has prompted a wave of policymakers and corporate giants to withdraw.
Just ahead of the three-day Future Investment Initiative (FII), dubbed "Davos in the desert", the kingdom sought to defuse the crisis with an about-face admission on Saturday that the journalist died in its consulate in Istanbul.
But that has failed to stem an exodus from the summit, whose organizers have taken down a list of speakers from its website.
US Treasury Secretary Steve Mnuchin Thursday tweeted that he has decided to withdraw from Saudi Arabia's FII conference next week.
Billed last year as an economic coming-out party for the conservative petro-state, the FII has now come to symbolize global outrage over the silencing of critics.
Crown Prince Mohammed bin Salman, widely known as MBS, faces what the risk consultancy Eurasia Group calls "an acute public relations crisis".
Siemens pressed by top politicians
Siemens boss Joe Kaeser came under pressure from senior German politicians on Sunday to pull out of the investment conference in Saudi Arabia next week.
Many business executives including the heads of Deutsche Bank, Uber Technologies and Siemens rival ABB have dropped out of Riyadh’s conference amid outrage about Khashoggi’s fate.
The leader of the Social Democrats (SPD), Andrea Nahles, called on Kaeser to follow the example of other executives and cancel his plans to attend the conference.
“I hope that Joe Kaeser will rethink this,” she told the Bild am Sonntag newspaper.
German Foreign Minister Heiko Maas, also from the SPD, told German public television on Saturday evening that cancellations sent the right signal.
“I certainly wouldn’t participate in an event in Riyadh at the moment,” he said. “And I have great understanding for those who have cancelled.”
Norbert Roettgen, a member of Chancellor Angela Merkel’s Christian Democratic Union who chairs the German parliamentary foreign affairs committee, also urged Kaeser to skip the event.
“This applies in my view, for example, to the Siemens CEO who has confirmed his attendance,” he told the Welt am Sonntag newspaper.
A spokesman for Siemens said Kaeser had not yet decided whether to attend the conference.
The engineering conglomerate has won orders to supply gas turbines, power plant components and trains to Saudi Arabia. Last year, it signed a declaration of intent to work with Saudi authorities to equip infrastructure projects which Siemens said could be worth at least a billion euros.
Many Western firms have too much at stake to abandon the Arab world's biggest economy, and many are preparing to send lower-level executives to the summit.
Senior investment bankers from HSBC and Credit Suisse are planning to attend the conference even though their chief executives have cancelled their attendance, Bloomberg News reported.
Companies from China and Russia have shown little interest in withdrawing from the event, an organizer said.
Although several Western leaders like International Monetary Fund chief Christine Lagarde have pulled out, Pakistan's Prime Minister Imran Khan will attend the forum as Islamabad continues to seek funding to plug its deteriorating finances.
But a wider Western boycott of the conference suggests rising political risks in Saudi Arabia that could cast a shadow over foreign direct investment, which a UN body said plunged last year to a 14-year low.
Dozens of executives – from bankers JP Morgan to carmaker Ford and ride-hailing app Uber – scrapped plans to attend.
Media powerhouses like Bloomberg, CNN and the Financial Times have also pulled out and on Saturday, Australia withdrew its representatives, saying it was "no longer appropriate" to attend, due to the Khashoggi affair.
On Saturday, organizers said more than 120 speakers and moderators will participate. Last Monday, they had listed more than 150 speakers.
The event seeks to project the historically insular kingdom as a lucrative business destination, in a bid to diversify its oil-reliant economy and set the stage for new ventures and multi-billion dollar contracts.
Reuters and AFP contributed to the story.