Ringo H.W. Chiu/Associated Press

Financial regulators questioned several aspects of Tesla's accounting this year.

The Securities and Exchange Commission wrote to Tesla's finance chief seeking more information about its finances and accounting policies, and queried the company's legal team over its withholding of information for competitive reasons.

The SEC closed its review in late October, and agreed Tesla could keep certain information redacted until 2020.

The agency sued Tesla CEO Elon Musk for fraud last year after he tweeted about taking Tesla private and said he had secured funding and support from investors.

The lawsuit resulted in a $40 million fine, Musk stepping down as chairman, and board changes.

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Financial regulators, after butting heads with Tesla CEO Elon Musk over his tweeting, questioned several aspects of his electric-car company's accounting this year.

The Securities and Exchange Commission queried Tesla's last annual report and its latest second-quarter report in a letter to Tesla's finance chief, Zachary Kirkhorn, on September 17, according to filings it shared this week.

The agency requested further explanation for changes in Tesla's accounts, sales by acquired companies to third parties, and its exclusion of some costs from its warranty reserve. The agency also asked for more details of Tesla's accounting of leased automobiles this year, following the release of new guidelines on their treatment.

Kirkhorn responded that the changes to Tesla's accounts — including a big jump in its production costs — were largely driven by scaled-up manufacturing of the Model 3. He added that some of the companies it acquired were still contracted to sell goods to third parties. He broadly defended Tesla's accounting of warranty reserves and lease accounting as kosher.

The SEC, seemingly satisfied with his reply, closed its review on October 28.

The agency also wrote to Tesla's legal team on September 17, seeking unredacted copies of some financial information to assess whether the company was within its rights to withhold it from SEC filings for competitive reasons. In a follow-up letter on September 25, it agreed certain information from Tesla's filings in 2017 and 2018 could be redacted until September 2020.

The correspondence suggests Tesla remains firmly on the SEC's radar.

The agency sued Musk for fraud in the fall of 2018 after he tweeted that he was thinking about taking Tesla private at $420 a share and had "funding secured," then added "investor support is confirmed."

The lawsuit resulted in a $40 million fine shared between Musk and his company, Musk stepping down as Tesla's chairman, and the company bolstering its board with new, independent directors.

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