Detroit Electric, a startup electric-car maker reviving a brand that dates back more than a century, unveiled its first model on Wednesday: a $135,000, battery-powered sports car that is to go into limited production in August.

Founded more than five years ago, Detroit Electric enters a still-nascent market that is struggling to find buyers. One of its would-be rivals, Fisker Automotive, a hybrid-electric sports-car company that hasn't built a car since last summer, has hired a law firm to advise on a possible bankruptcy filing.