General Motors Co. is developing an electric car that can go 200 miles on a charge for around $30,000, officials at the largest U.S. auto maker said, offering a challenge to luxury electric-car startup Tesla Motors Inc.

Doug Parks, GM's vice president of global product programs, disclosed the effort on Monday at GM's battery laboratory and test facility in Warren, Mich., but didn't say when the car would be available. He said while the technology is available now, the cost of the batteries remains too high to be able to...