ImageRobyn Denholm, Tesla’s new chairwoman, has an extensive background in technology.CreditCreditTesla Inc., via Associated PressUnder regulatory pressure, Tesla has named a new leader for its board as it tries to allay concerns about its stability under Elon Musk, its colorful but erratic co-founder.The electric-car company said Wednesday night that Robyn Denholm, a board member since 2014 and a longtime technology and telecommunications executive, would become its chairwoman immediately. Mr. Musk will remain Tesla’s chief executive. Ms. Denholm is currently the chief financial officer of Telstra, which dominates telecommunications in Australia.The move to replace Mr. Musk as chairman was part of a settlement reached with the Securities and Exchange Commission in September to deal with the fallout from his Twitter post in August that he had secured funding for a private buyout of the company. That claim quickly fell into doubt. (Mr. Musk later explained in a blog post that discussions with Saudi Arabia’s sovereign wealth fund led him to believe that it had both money and enthusiasm for such a deal.)Under that settlement, Tesla agreed to name a new chairman, splitting those responsibilities from Mr. Musk’s post as chief executive, by next Tuesday.The company was also required to add two independent board members and to set up a permanent committee to monitor Mr. Musk’s public declarations, including his Twitter posts.Erik Gordon, a professor at the University of Michigan’s Ross School of Business, said the appointment of Ms. Denholm “technically complies” with the S.E.C. settlement, but questioned how much Ms. Denholm would be able to push back against a forceful personality like Mr. Musk.“If the goal is to provide adult supervision, it won’t accomplish that,” Mr. Gordon said. “She’s been on the board through all of the shenanigans. She never resigned in protest. She is a Musk supporter. If it doesn’t work out, she will be the one who leaves. It won’t be Musk who leaves.”David Whiston, an analyst at Morningstar who follows Tesla, said the appointment was a “a good balance” and was probably best for Tesla’s stock price. Bringing in a hard-nosed outsider “who wouldn’t put up with Elon’s Twitter nonsense,” he added, “would clash with Elon and it wouldn’t work at all.”Tesla shares were up about 1 percent in afternoon trading on Thursday.Still, Mr. Whiston also expressed doubts about how much Ms. Denholm will be able to rein in Mr. Musk. In the last few weeks, the chief executive referred to the S.E.C. on Twitter as the “Shortseller Enrichment Commission,” and then announced that he no longer had a title at Tesla, raising questions about whether he would continue to have the final word, even with a new leader of the board.ImageTesla announced a new chairwoman after a settlement with security regulators over fallout from a Twitter post by Elon Musk.CreditBrian Snyder/Reuters“It’s troubling to me that since the settlement Elon has already made a mockery of the S.E.C. twice,” Mr. Whiston said. He said Mr. Musk should “stop playing games and just make the darn cars.”Tesla’s new chairwoman has an extensive background in technology. Before her current position at Telstra, Ms. Denholm was an executive at Juniper Networks, which makes computer networking equipment, for about a decade.She also has experience in the auto industry. She spent seven years at Toyota Motor Corporation Australia, where she was national manager for finance, before leaving in 1996 for Sun Microsystems, a onetime Silicon Valley powerhouse later acquired by Oracle.Tesla said Ms. Denholm would step down from her role at Telstra once her six-month notice period is complete.Mr. Whiston said Ms. Denholm’s plan to leave Telstra “shows commitment to Tesla to make sure this oversight is done properly.” But Professor Gordon cautioned that once she left her Telstra position, being chairwoman of Tesla “will be her full-time gig,” making her less likely to confront Mr. Musk. “It will be a job she doesn’t want to lose,” he said.Mr. Musk heralded the change in typical fashion — on Twitter.In the Tesla announcement, Mr. Musk cited Ms. Denholm’s experience and years with his company. “Robyn has extensive experience in both the tech and auto industries, and she has made significant contributions as a Tesla board member over the past four years in helping us become a profitable company. I look forward to working even more closely with Robyn as we continue accelerating the advent of sustainable energy.”Mr. Musk has galvanized investors and the public imagination with his sleek electric cars and his big dreams for space travel and other ambitions. But his public declarations increasingly unnerved Tesla shareholders and the board directors who represent them. Production problems at Tesla only added to those concerns.In addition to his troublesome tweet about a buyout, Mr. Musk showed other signs of stress. He had a nasty social media battle with a British diver involved in the daring rescue of 12 boys in a flooded cave in Thailand this summer — a spat he had to quickly walk back.In August, Mr. Musk told The New York Times that this year “has been the most difficult and painful year of my career,” in part because of the pressure of running Tesla, and that he sometimes took the insomnia drug Ambien to sleep. Some board members worried the drug was contributing to his late-night Twitter sessions.In September, he appeared to briefly smoke marijuana during an interview with Joe Rogan, a comedian. (The interview took place in California, where recreational marijuana use is legal.)The S.E.C. settlement was intended to lay some of those concerns to rest. Last month, Tesla posted positive financial results, suggesting it is beginning to resolve some of its problems.Follow Carlos Tejada and Neal E. Boudette on Twitter: @CRTejada and @nealboudette.