The U.S. Securities and Exchange Commission, Tesla Inc and Chief Executive Officer Elon Musk submitted a joint filing late on Wednesday in support of a settlement, saying the terms were in the best interest of investors.

"We therefore respectfully submit that the court should accept and enter the proposed consent judgments," they said in a letter filed with the U.S. District Court, Southern District of New York.

Last week, a federal judge had ordered the SEC and Musk to justify their securities fraud settlement, which let Musk remain CEO, by Oct. 11.

Musk agreed to pay a $20 million fine, and step aside as Tesla's chairman for three years, to settle charges that could have forced his exit from Tesla. The company also accepted a $20 million fine, despite not being charged with fraud.

However, Musk appeared to mock the SEC on Twitter last Thursday, just hours after the court ordered him and the SEC to explain why their settlement was fair and reasonable. 

"Just want to sic that the Shortseller Enrichment Commission is doing incredible work," Musk, a frequent critic of investors betting against the electric car company, wrote. "And the name change is so on point!"

Tesla shares were down 1.3 percent at $253.5 in premarket trading.

(Reporting by Rama Venkat and Munsif Vengattil in Bengaluru; Editing by Gopakumar Warrier, Bernard Orr) ((ramavenkat.raman@thomsonreuters.com; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 7151; Reuters Messaging: ramavenkat.raman.thomsonreuters.com@reuters.net))