DETROIT—General Motors Co. and Nikola Corp. on Monday announced a reworked agreement on a fuel-cell partnership that eliminates an equity stake in the startup for the Detroit automaker as well as plans for building Nikola’s electric pickup truck, sending Nikola shares tumbling almost 22 percent.
In September, the companies announced a deal under which GM would supply batteries, a chassis architecture, fuel cell systems, and a factory to build Nikola’s proposed Badger electric pickup in return for an 11 percent stake and $700 million.
