SoftBank Group Corp. has prepared a financing package that would give it control of WeWork and further sideline its founder Adam Neumann in exchange for relieving the shared-office startup’s looming cash crunch, according to people familiar with the matter.

WeWork is racing to find a way to shore up its financing after its New York parent company We Co. pulled its plans for an initial public offering and Mr. Neumann resigned as chief executive under pressure.

One...