The Justice Department’s investigation of manipulation in the precious-metals markets at JPMorgan Chase & Co. spurred prosecutors to ask a judge to delay a civil lawsuit focusing on similar misconduct.

Former trader John Edmonds pleaded guilty last month to federal charges that he placed hundreds of orders in the futures market he never intended to execute, in a six-year spoofing scheme. On Monday, the Justice Department asked the judge overseeing an antitrust lawsuit against JPMorgan to delay the case for six months to “protect the integrity” of its ongoing criminal probe.