FILE PHOTO - Tesla and SpaceX CEO Elon Musk participates in a "fireside chat" at the National League of Cities (NLC) 2018 City Summit in Los Angeles, California, U.S. November 8, 2018. REUTERS/Kyle Grillot

(The Nov. 26 story corrects paragraphs 4 and 5 to show the SEC filed charges against Musk and Tesla, and that Musk and Tesla settled those charges without admitting or denying the SEC’s allegations)

WASHINGTON (Reuters) - The U.S. Securities and Exchange Commission chairman said on Monday that the agency would not revisit its securities fraud settlement with Tesla Inc despite Chief Executive Elon Musk’s tweet mocking the regulator.

Jay Clayton appeared to be unaware of the Oct. 4 tweet describing the SEC as the “Shortseller Enrichment Commission,” when CNBC anchors read it to him on Monday.

“He said that?” Clayton asked, declining to comment further. “As far as I’m concerned, that matter is settled.”

Tesla and Musk agreed in September to pay $20 million each to settle SEC charges over Musk’s tweets on Aug. 7 that said he was considering taking Tesla private and had secured funding for such a deal.

Musk and Tesla settled the charges against them without admitting or denying the SEC’s allegations.

The settlement requires him to be more restrained on Twitter, prompting speculation that the agency could review the agreement after Musk’s Oct. 4 tweet which came hours after a federal judge ordered him and the SEC to justify their settlement. Shares of the electric carmaker fell as much as 4 percent after that tweet.

“I think it was an appropriate settlement; one that sent a message to the marketplace, letting CEOs know that if they speak, they need to speak accurately,” Clayton said.