Japan’s SoftBank Group Corp. is in talks to purchase a large chunk of shares in the upcoming initial public offering of Chinese electric-vehicle maker NIO, according to people familiar with the matter, a move that could help bolster a multibillion-dollar valuation for the startup.
Shanghai-based NIO, an emerging rival to Tesla Inc., last December launched its first production car model—a seven-seater electric sport-utility vehicle—and has started taking customer orders for it. The company is working on a plan to list in New...