In a yearslong dispute between a PSE&G subsidiary and its steel supplier, a New Jersey appeals court on Monday, reinstating the action, said a trial judge erred in blocking an executive’s testimony and requiring an expert report.

The three-judge Appellate Division panel, in a published decision, ordered a new trial for the plaintiff, Midland City, Alabama-based E&H Steel Corp., which filed the lawsuit against Newark-based PSEG Fossil LLC, a subsidiary of PSEG Power LLC.