General Motors said on Friday that plaintiffs’ lawyers suing over a faulty ignition switch linked to nearly 400 injuries and deaths have chosen to dismiss what was scheduled to be the fourth in a series of six test trials over the defect covering about 235 injury and wrongful-death cases that are pending in state and federal courts. The decision came a day after G.M. settled what was to be the third lawsuit to go to trial, and followed a win for the automaker a week ago in the first of the so-called bellwether trials to reach a verdict. G.M. has admitted some employees knew about the problems for years, and has paid about $ 2 billion in settlements and penalties over the defect. The fourth case set for trial was brought by Robert Reid, an Alabama resident suing over injuries he sustained in a 2013 accident. But in a filing in federal court in Manhattan on Friday, G.M. and his lawyers said the case would be dismissed. A G.M. spokesman said there was no settlement as part of the dismissal. A lawyer for Mr. Reid did not respond to requests for comment.