Tesla Inc. is looking to raise as much as $2.3 billion through a bond and stock sale after the electric-car maker reported a steep quarterly loss last week that heightened concerns about its dwindling reserves of cash.

Tesla shares, which have been under pressure, rose Thursday as investors said they welcomed the fresh injection of capital. Fidelity Investments, T. Rowe Price Group Inc. and other fund managers have sold millions of shares in 2019 amid concerns about the firm’sfinances and performance.

Chief Executive Elon Musk had said Tesla didn’t need to seek new financing as the Silicon Valley company wrestled with manufacturing and logistic challenges in bringing its mass-market Model 3 sedan to customers.

That message shifted last week after Tesla reported one of its worst quarterly losses in history, and its cash fell by more than 40% to $2.2 billion from three months earlier. Mr. Musk said then that Tesla was operating more efficiently, but that there was “merit to the idea” of raising money.

Tesla said Thursday that it expects to bring in about $642.3 million in net proceeds from a public offering of about 2.7 million shares. Mr. Musk signaled his intent to buy about $10 million of those shares.