Tesla CEO Elon Musk, who turned an upstart electric vehicle maker into an industry-changing powerhouse, is pulling the plug on the two models that helped get him there, as he struggles with another quarter of declining profits and car sales.

Tesla is planning to end production of its Model S luxury electric sedan and Model X luxury electric SUV in the spring in favor of plan to build robots, the company's CEO Elon Musk told investors on T...