A federal judge in California has asked plaintiffs lawyers suing Volkswagen for rigging U.S. emissions testing results to suggest the best person to oversee settlement of more than 500 class actions.

The selection of a special settlement master is not uncommon, but it usually takes place much later in the course of ­litigation. Many plaintiffs lawyers have predicted that Volkswagen could ­quickly settle the litigation, having already admitted that 11 million cars and trucks have a “defeat device” in them designed to cheat emissions tests, including 482,000 in the United States.