He tweeted later he was working with Goldman Sachs Group Inc (GS.N) and Silver Lake as financial advisers, though a source said the private equity firm was working in an unpaid, informal capacity and also not discussing participating as an investor.
Musk said in his Monday statement that he was still in talks with the Saudi fund but was also having discussions with other investors because he wanted to "continue to have a broad investor base".
Shares in Tesla, which are still well below highs hit when Musk initially raised the prospect of the transaction last week, inched up 0.7% in trading before the bell.
"The special committee has not yet received a formal proposal from Mr. Musk regarding any Going Private Transaction", the company said in a public filing with US securities regulators, the first it has made since Musk's tweets last week. Musk further claimed that he had the "funding secured" to take the company private, an act that would cost up to $70 billion.
Annual meteor shower to peak Sunday night
This year, the Perseids shower will last overall from August 10 to 14, with the peak taking place this weekend. Whilst meteors can be seen on any night, at certain times of the year their numbers drastically increase.
Musk said his decision to announce his negotiations publicly was in the interest of all investors, as it wouldn't have been fair to only tell the largest share holders.
PIF officials have said in the past that decisions at the sovereign wealth fund are made with care, emphasising corporate governance.
That tweet may have created a sticky situation for Musk as it appears the funding may not be locked up yet.
Musk on Monday estimated two-thirds of existing Tesla shareholders would roll over their holdings into a private company, but said that he was still talking with major shareholders and advisers before settling on a structure for the deal.
"Despite Elon Musk's frustration with being a public company, I think there are more advantages to remaining public", said CFRA analyst Efraim Levy, citing cheaper access to capital and media exposure due to interest in a public company. Jeremy Zucker, co-head of Decherts International Trade practice, said two key determinations would be made if a deal moved forward: whether Tesla contained critical technologies and whether the involvement of Saudi financing was a national security issue.