Tesla CEO Elon Musk ended nearly a week of speculation Monday by revealing the “secured” source of financing for his plan to take the electric automaker private — the sovereign wealth fund of oil-rich Saudi Arabia.

In a post on the company’s blog, Musk said the fund’s managers first approached him with the idea in early 2017 and have met with him multiple times to pursue it. For the Saudis, such an investment would help achieve the kingdom’s goal of diversifying beyond oil, the cornerstone of the country’s economy.

The fund recently purchased a 5 percent stake in Palo Alto’s Tesla, Musk wrote. The fund’s managers then met with Musk again, on July 31, with the managing director again expressing support for going private.

News of the fund’s investment finally broke on Aug. 7. Hours later, Musk tweeted that he was considering taking Tesla private at $420 per share, saying he already had funding for the proposed deal lined up.

At the time, however, he did not identify the source of the funding, leading some analysts to question whether he truly had backing for the deal. The U.S. Securities and Exchange Commission, according to the Wall Street Journal, inquired whether he had misled investors.

“I left the July 31st meeting with no question that a deal with the Saudi sovereign fund could be closed, and that it was just a matter of getting the process moving,” Musk wrote Monday. “This is why I referred to ‘funding secured’ in the August 7th announcement.”

Musk wrote that he is now meeting with major shareholders to discuss the proposal. In order for the deal to go through, Musk wrote that he would first present a detailed proposal to Tesla’s board, which would create a special committee to evaluate it. If approved by the board as well as government regulators, the plan would be presented to Tesla shareholders for a vote.

Musk added, however, that he would not propose a detailed plan before meeting with more investors, saying that to do otherwise would be “premature.” He also wants to work with advisers to “investigate a range of potential structures and options.” He emphasized, however, that he wants to ensure that any current shareholders who wish to remain with Tesla can do so.

“My best estimate right now is that approximately two-thirds of shares owned by all current investors would roll over into a private Tesla,” he wrote.

As a result, he said, the deal would cost significantly less than the $70 billion that some reports estimated. Tesla had 170 million basic shares outstanding at the end of the second quarter, so paying $420 each for one third of those shares would cost about $24 billion.

Musk’s initial tweet last week about going private caused Tesla’s share price to spike, although the stock gave up most of those gains in the following days. In contrast, his Monday blog post, released before the start of trading, appeared to have no impact on the company’s stock. It rose less than 1 percent to close at $356.41.

Venture capitalist Gene Munster, managing partner of Loup Ventures, wrote Monday that Musk’s explanation of his discussions with the Saudis would probably be enough to dismiss the possibility of his facing stock-manipulation charges from the SEC. At the same time, two class-action suits have already been filed over Musk’s initial tweets about the deal.

“We still believe there is a greater than 50% chance Tesla is private in a year, and the blog post slightly increased those odds,” Munster wrote.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF